Method and device for performing communication on basis of wake-up signal in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A method performed by a terminal according to one embodiment of the present disclosure may transmit terminal capability information related to an LP-WUS to a base station. The method may receive an RRC message including information related to the LP-WUS and activation information from the base station. When the reception function of the LP-WUS is activated, the method may monitor the LP-WUS for PDCCH reception. The method may receive the PDCCH on the basis of the monitoring result.

Description

Method and device for performing communication based on a wake-up signal in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to conditions under which terminals having a wake-up receiver can receive a wake-up signal based on the implementation of the wake-up receiver, and operation procedures and devices of the terminal according to the conditions.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by leveraging eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] As a result of the development of mobile communication systems and the aforementioned advancements in technology, various services have become available, and methods for effectively providing these services are required, and in particular, methods for reducing power consumption of terminals are required.

[0009] The present disclosure provides conditions to be satisfied before or during performing an operation of monitoring a wake-up signal so as to reduce power consumption of a terminal having a wake-up receiver in a wireless communication system, and an operation method and device of the terminal according to the conditions.

[0010] According to one embodiment of the present disclosure, a method performed by a terminal in a wireless communication system may include a step of transmitting terminal capability information related to a Low Power Wake Up Signal (LP-WUS) to a base station. The method may include a step of receiving an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information from the base station. The method may include a step of monitoring the LP-WUS for PDCCH (Physical Downlink Control Channel) reception when a reception function of the LP-WUS is activated. The method may include a step of receiving the PDCCH based on a monitoring result.

[0011] A terminal performing communication according to one embodiment of the present disclosure may include a transceiver and at least one processor connected to the transceiver. The at least one processor may transmit terminal capability information related to a Low Power Wake Up Signal (LP-WUS) to a base station. The at least one processor may receive an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information from the base station. The at least one processor may monitor the LP-WUS for Physical Downlink Control Channel (PDCCH) reception when a reception function of the LP-WUS is activated. The at least one processor may receive the PDCCH based on a monitoring result.

[0012] According to one embodiment of the present disclosure, in a method for a base station to perform communication in a wireless communication system, the method may include a step of receiving terminal capability information related to a Low Power Wake Up Signal (LP-WUS) from a terminal. The method may include a step of transmitting an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information to the terminal. The method may include a step of transmitting a Physical Downlink Control Channel (PDCCH) based on a monitoring result for the LP-WUS for PDCCH reception when the LP-WUS is activated.

[0013] In addition, a method performed by a base station in a wireless communication system includes a step of transmitting a wake up signal (WUS) to a terminal having a wake up receiver (WUR), and a step of receiving feedback information for the WUS from the terminal, wherein the WUS may include at least one of a WUS for checking coverage and a WUS for changing a state of a main radio receiver of the terminal.

[0014] In addition, a method performed by a terminal of a wireless communication system comprises: a step of checking configuration information for a WUS (wake up signal); a step of detecting the WUS through a WUR (wake up receiver) based on the configuration information; a step of triggering a main radio to turn on in response to detection of the WUS; and a step of receiving a signal from a base station through the main radio, wherein the WUS is received as a common WUS that can be received regardless of the type of WUR.

[0015] In addition, a method performed by a base station of a wireless communication system comprises: a step of checking setting information for a WUS (wake up signal); a step of transmitting the WUS according to the setting information to a terminal; and a step of transmitting a signal to the terminal, wherein the WUS transmits a common WUS that can be received regardless of the type of WUR.

[0016] In addition, in a terminal of a wireless communication system, a main radio including a transceiver; a WUR (wake up receiver) that detects a WUS (wake up signal); and a control unit that controls the main radio and the WUS, wherein the control unit checks setting information for the WUS (wake up signal), triggers the WUR to detect the WUS based on the setting information, turns on the main radio in response to detection of the WUS, and sets the WUR and the main radio to receive a signal from a base station through the main radio, and the WUS is characterized in that it is received as a common WUS that can be received regardless of the type of WUR.

[0017] In addition, in a base station of a wireless communication system, a transmitter / receiver unit; and a control unit configured to check setting information for a WUS (wake up signal), transmit the WUS according to the setting information to a terminal, and set the terminal to transmit a signal, wherein the WUS is transmitted as a common WUS that can be received regardless of the type of WUR.

[0018] In addition, a method for a terminal to perform communication in a wireless communication system can receive information related to a Wake Up Signal (WUS). The method can determine whether to activate a WUS reception function based on the information related to the WUS. If the WUS reception function is activated, the method can monitor the WUS for PDCCH (Physical Downlink Control Channel) reception. The method can receive the PDCCH based on the monitoring result.

[0019] Figure 1 is a diagram illustrating an example of the basic structure of the time-frequency resource domain of a 5G system.

[0020] FIG. 2 is a diagram illustrating an example of a time domain mapping structure and beam sweeping operation of a synchronization signal.

[0021] Figure 3 is a diagram illustrating an example of a random access procedure.

[0022] Figure 4 is a diagram illustrating an example of a procedure in which a terminal reports terminal capability information to a base station.

[0023] FIG. 5 is a diagram illustrating an example of an operation in which a base station instructs a terminal with WUR to switch to the main radio state through WUS.

[0024] Figure 6a illustrates an example of an operation performed by a terminal in RRC IDLE and INACTIVE states to receive a paging message transmitted by a base station.

[0025] Figure 6b illustrates an example of an operation performed by a terminal in an RRC CONNECTED state to receive a PDCCH transmitted by a base station in a situation where DRX is operating.

[0026] Figure 7 is a drawing illustrating an example of a base station's status and status change procedure depending on whether LP-WUS transmission is performed.

[0027] Figure 8 is a drawing illustrating an example of operations and procedures required for a terminal capable of receiving LP-WUS to receive LP-WUS.

[0028] FIG. 9 is a diagram illustrating an example of an operation procedure in which the LP-WUS function is disabled due to a terminal that does not satisfy the entry conditions for activating the LP-WUS function or an exit procedure.

[0029] FIG. 10 is a block diagram illustrating an example of the structure of a terminal according to one embodiment of the present disclosure.

[0030] FIG. 11 is a block diagram illustrating an example of the structure of a base station according to one embodiment of the present disclosure.

[0031] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0032] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to ensure that the gist of the present disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0033] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. In each drawing, identical or corresponding components are assigned the same or different reference numbers.

[0034] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification. In addition, when describing the present disclosure, if a specific description of a related function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions of the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the specification.

[0035] In the present disclosure, it will be appreciated that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed based on computer program instructions. These computer program instructions can be selectively installed in at least one processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by any one or any combination of at least one processor of the computer or other programmable data processing equipment create means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce an article of manufacture that includes instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0036] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks (or functions) depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on the corresponding function.

[0037] The term '~ unit' used in the embodiments of the present disclosure means a software or hardware component such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and the '~ unit' performs certain roles. However, terms including '~ unit' are not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~parts' may be implemented to play one or more central processing units (CPUs) within the device or secure multimedia card. Also, in an embodiment, the '~parts' may include one or more processors.

[0038] As described above, it should be noted that the blocks and combinations of flowcharts described in the present disclosure may be implemented by one or more computer programs containing instructions. One or more computer programs may be stored entirely in a single memory device, or one or more computer programs may be divided and stored in different portions across multiple memory devices.

[0039] Additionally, any / any function or operation described in the present disclosure may be processed by a single processor or a combination of processors. The single processor or the combination of processors may include circuitry that performs processing, such as an application processor (AP, e.g., a central processing unit (CPU)), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, a Bluetooth® chip, a global positioning system (GPS) chip, a near-field communication (NFC) chip, a connectivity chip, a sensor controller, a touch controller, a fingerprint sensor controller, a display driver integrated circuit (IC), an audio codec (CODEC) chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on a chip (SoC), an IC, or similar circuitry.

[0040] It should also be noted that the various embodiments in the claims and description of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0041] Such software may be stored on a non-transitory computer-readable storage medium. The non-transitory computer-readable storage medium stores one or more computer programs (software modules), wherein the one or more computer programs include computer-executable instructions that, when executed alone or collectively by one or more processors of an electronic device, cause the electronic device to perform a method according to the present disclosure.

[0042] The software may be stored in a temporary or non-transitory storage device, for example, in the form of a read-only memory (ROM) (whether erasable or rewritable), a random access memory (RAM), a memory chip, a device, or an integrated circuit (IC). Furthermore, the software may be stored in the form of an optically or magnetically readable medium, for example, a compact disc (CD), a digital versatile disc (DVD), a magnetic disk, or a magnetic tape. It should be understood that the storage device and the storage medium are examples of non-transitory machine-readable storage media suitable for storing a program for implementing various embodiments of the present disclosure. Accordingly, various embodiments of the present disclosure may provide a program comprising code for implementing a device or method according to any one of the claims of the present specification, and a non-transitory machine-readable storage medium storing such a program.

[0043] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0044] Hereinafter, 'A or B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0045] Additionally, 'at least one of A, B, and C' described in the present disclosure may be understood to include 'A', or 'B', or 'C', or 'any combination of A, B, and C'.

[0046] Additionally, 'at least one of A, B, or C' described in the present disclosure may be understood to include 'A', or 'B', or 'C', or 'any combination of A, B, and C'.

[0047] Additionally, 'A / B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0048] Additionally, 'A, B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0049] Additionally, 'A and B' described in the present disclosure may be understood as 'A and / or B', which may be understood to include 'A', or 'B', or 'A and B'.

[0050] In addition, it can be understood that the 'case where conditions A and B are satisfied' described in the present disclosure is not necessarily limited to the case where both conditions A and B are satisfied, but may include the case where each of conditions A or B is satisfied, the case where both conditions A and B are satisfied, or the case where one or more additional conditions are satisfied together.

[0051] Additionally, throughout this specification, ordinal terms such as "first," "second," "third," and the like (and modifiers thereof) are used solely to distinguish between various instances, occurrences, configurations, messages, stages, or aspects of elements, operations, or information, as described below. Unless the context clearly requires otherwise, the use of such ordinal terms does not require that the elements, operations, or information distinguished by them be structurally, numerically, or inherently different. For example, "a first signal" and "a second signal" may represent instances of the same signal transmitted at different times, may represent signals containing the same core information albeit with some modifications, or may represent signals having different content or characteristics depending on the specific context. Similarly, "a first value" and "a second value" may represent measurements or applications of the same magnitude in different circumstances, or may represent different magnitudes. Such interpretation should be determined by the specific technical context, functions and relationships described in the relevant portions of the specification and claims.

[0052] Furthermore, although terms such as "first" and "second" described in this disclosure are used to refer to various elements such as information, objects, actions, and sequences, they are not intended to limit such elements to a specific order. These terms may be understood to be used merely to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0053] Additionally, it may be understood that the terms "first~" and "second~" described in this disclosure may refer to the same or different elements. For example, if the elements are information, the first information and the second information may both be information, and in some cases, they may be the same information or different information.

[0054] In addition, the expressions "if" and "in case that" described in the present disclosure or claims may be interpreted to mean "when or upon," "in response to," or "based on," or "according to," depending on the context, and these expressions may be used interchangeably. In addition, in addition to these expressions, other expressions having substantially the same meaning may be used interchangeably, within the scope that does not impair the technical features of the present disclosure.

[0055] Additionally, the term "not perform" as used in this disclosure or claims may be understood to mean omitting or skipping a step, depending on the context. Such terms may be replaced with other terms having the same or substantially similar meaning.

[0056] Additionally, "transmitting a message including A and B" as described herein may be interpreted to include both (i) cases where A and B are transmitted in a single message, as well as (ii) cases where A and B are transmitted individually via multiple messages (e.g., transmitting a first message including A and a second message including B). This interpretation may also apply when a message including two or more items, such as A, B, and C, is transmitted together or individually.

[0057] Additionally, 'sending a message containing A and sending a message containing B' can also be interpreted as sending a single message containing A and B.

[0058] In the specific embodiments of the present disclosure described below, terms or components included in the disclosure will be expressed in the singular or plural, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural may be composed of singular elements, or components expressed in the singular may be composed of plural elements.

[0059] The drawings or flowcharts described below illustrate exemplary methods that may be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts of the present disclosure. For example, although depicted as a series of steps, various steps in each drawing or flowchart may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, any step may be omitted or replaced with another step.

[0060] The methods and devices proposed in the embodiments of the present disclosure are not limited to each embodiment, and may be utilized as a combination of one or more embodiments, all or part of the embodiments proposed in the disclosure. Accordingly, the embodiments of the present disclosure may be applied with some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as determined by a person skilled in the art.

[0061] In this case, even if any wording is mentioned in different embodiments, if the concepts correspond, they may be used interchangeably, combined, or substituted. For example, for identical or corresponding concepts, even if one embodiment uses the expression "A" and another embodiment uses the expression "B," these may be understood interchangeably, substituted, or combined.

[0062] In the following description, terms used to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used. In addition, the terms may be replaced with terms defined in the 3rd generation partnership project (3GPP) Technical Specifications (TS), if appropriate.

[0063] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (base station), a radio access unit, a base station controller, or a node on a network. In addition, the base station of the present disclosure may include a structure that is split into a central unit (CU) and a distributed unit (DU). In this structure, the CU is responsible for the upper layers of the control and user planes, and the DU is responsible for radio resource processing of the lower layers. The embodiments of the present disclosure can be equally applied to a 5G base station structure in which functions are separated into the CU and DU.

[0064] The terminal may include a UE (user equipment), MS (mobile station), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions.

[0065] In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station.

[0066] In addition, although the fifth generation mobile communication system (5G, new radio, NR) and the sixth generation mobile communication system (6G) may be described below as examples, the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, this may include new evolved mobile communication systems developed after 5G and 6G. In addition, the present disclosure may be applied to other communication systems (e.g., Wi-Fi systems) with some modifications within a range that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge.

[0067] In the following description, the terms "physical channel" and "signal" may be used interchangeably with data or control signals. For example, while PDSCH (physical downlink shared channel) refers to a physical channel through which data is transmitted, PDSCH may also be used to refer to data. That is, in the present disclosure, the expression "transmitting a physical channel" may be interpreted equivalently to the expression "transmitting data or a signal through a physical channel."

[0068] In the following description of the present disclosure, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of MIB (master information block), SIB (system information block), SIB M (M=1, 2, …), RRC (radio resource control), MAC (medium access control) CE (control element), NAS (non-access stratum) signaling, or application layer messages. The RRC signaling may also be referred to as L3 signaling (layer 3 signaling).

[0069] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using a physical layer channel or signaling of PDCCH (physical downlink control channel), DCI (downlink control information), UE-specific DCI, group common DCI, common DCI, scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data), non-scheduling DCI (e.g., DCI not for the purpose of scheduling downlink or uplink data), physical uplink control channel (PUCCH), or uplink control information (UCI). The L1 signaling may also be referred to as physical layer signaling.

[0070] Hereinafter, the expression that information can be configured from a base station in the present disclosure or claims may mean that a terminal receives the information from the base station through physical layer signaling or upper layer signaling, depending on the context, and such expression may be replaced with other terms having the same or substantially similar meaning.

[0071] The operating principle of the present disclosure is described in detail with reference to the attached drawings below.

[0072] To handle the explosive increase in mobile data traffic, the initial standards for the 5G (5th Generation) system or New Radio access technology (NR), the next-generation communication system following LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)) and LTE-A (LTE-Advanced or E-UTRA Evolution), have been completed. While existing mobile communication systems have focused on conventional voice / data communications, the 5G system aims to satisfy various services and requirements, such as the eMBB (enhanced Mobile BroadBand) service for improving existing voice / data communications, the URLLC (Ultra-Reliable and Low Latency Communication) service for high reliability / ultra-low latency, and the massive MTC (Machine Type Communication) service that supports massive machine-type communication.

[0073] While the transmission bandwidth of existing LTE and LTE-A systems per single carrier is limited to a maximum of 20MHz, the 5G system aims to provide ultra-high-speed data services of up to several Gbps by utilizing an ultra-wide bandwidth that is much wider than this. Accordingly, the 5G system is considering ultra-high frequency bands from several GHz up to 100 GHz as candidate frequencies, where securing ultra-wide bandwidth frequencies is relatively easy. Additionally, it is possible to secure wide bandwidth frequencies for the 5G system through frequency reallocation or allocation among frequency bands included in the hundreds of MHz to several GHz used in existing mobile communication systems.

[0074] Radio waves in the ultra-high frequency band are sometimes called millimeter waves (mmWave) because their wavelengths are on the order of millimeters. However, in the ultra-high frequency band, the path loss of radio waves increases in proportion to the frequency band, reducing the coverage of mobile communication systems.

[0075] In order to overcome the disadvantage of reduced coverage in the above ultra-high frequency band, beamforming technology is applied, which uses multiple antennas to concentrate the radiated energy of radio waves to a predetermined target point and thereby increase the transmission distance of radio waves. That is, a signal to which the beamforming technology is applied has a relatively narrow beam width of the signal, and the radiated energy is concentrated within the narrowed beam width, thereby increasing the transmission distance. The beamforming technology can be applied to both the transmitter and the receiver. In addition to the effect of increasing coverage, the beamforming technology has the effect of reducing interference in areas other than the beamforming direction. In order for the beamforming technology to operate properly, accurate measurement and feedback methods of the transmission / reception beams are required. The beamforming technology can be applied to a control channel or data channel that corresponds one-to-one between a predetermined terminal and a base station. Additionally, beamforming technology can be applied to common signals transmitted by a base station to multiple terminals within a system, such as synchronization signals, physical broadcast channels (PBCH), control channels for transmitting system information (or system information block, SIB), and data channels, to increase coverage. When beamforming technology is applied to common signals, beam sweeping technology, which transmits signals by changing the beam direction, is additionally applied so that the common signal can reach terminals located at any location within a cell.

[0076] Another requirement for 5G systems is ultra-low latency services, with transmission delays of approximately 1 ms between transmitters and receivers. One way to reduce transmission delay is to design a frame structure based on a shorter transmission time interval (TTI) than in LTE and LTE-A. A TTI is the basic unit of time for scheduling, and the TTI of existing LTE and LTE-A systems is 1 ms, which corresponds to the length of one subframe. For example, to meet the requirements for ultra-low latency services in the 5G system, possible TTIs are 0.5 ms, 0.25 ms, and 0.125 ms, which are shorter than those of existing LTE and LTE-A systems.

[0077] According to one embodiment of the present disclosure, by defining a signal transmission method of a terminal having a wake-up receiver in a mobile communication system, the problem of excessive terminal power consumption can be solved and high energy efficiency can be achieved.

[0078] Figure 1 is a diagram illustrating an example of the basic structure of a time-frequency resource domain of a 5G system. That is, Figure 1 illustrates the basic structure of a time-frequency resource domain, which is a radio resource domain in which data or control channels of a 5G system are transmitted.

[0079] Referring to Figure 1, the horizontal axis in Figure 1 represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain of the 5G system is an OFDM (orthogonal frequency division multiplexing) symbol. (102) symbols are grouped together to form one slot (106), A plurality of slots can be grouped to form a subframe (105). The length of the subframe is 1.0 ms, and 10 subframes can be grouped to form a 10 ms frame (114). The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth can be composed of a total of NBW (104) subcarriers.

[0080] The basic unit of resources in the time-frequency domain is a resource element (RE, 112), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB or physical resource block, PRB) is a resource block in the frequency domain. It can be defined as (110) consecutive subcarriers. In 5G systems, =12, and the data rate can increase in proportion to the number of RBs scheduled to the terminal.

[0081] In a 5G system, a base station can map data in RB units and perform scheduling on RBs, which typically constitute a slot for a given terminal. That is, in a 5G system, the basic time unit for scheduling may be a slot, and the basic frequency unit for scheduling may be an RB.

[0082] Number of OFDM symbols It is determined by the length of the cyclic prefix (CP) added to each symbol to prevent interference between symbols. For example, if the normal CP is applied, = 14, when extended CP is applied = can be 12. Extended CP is applied to a system with a relatively long transmission distance than the general CP, and can maintain orthogonality between symbols. In the case of the general CP, since the ratio of the CP length to the symbol length is maintained at a constant value, the overhead due to the CP can be maintained constant regardless of the subcarrier spacing. That is, if the subcarrier spacing is small, the symbol length becomes longer, and thus the CP length can also become longer. Conversely, if the subcarrier spacing is large, the symbol length becomes shorter, and thus the CP length can be reduced. The symbol length and CP length can be inversely proportional to the subcarrier spacing.

[0083] In 5G systems, various frame structures can be supported by adjusting the subcarrier spacing to meet diverse services and requirements. For example,

[0084] - From the perspective of the operating frequency band, the larger the subcarrier spacing, the more advantageous it is for recovering phase noise in the high-frequency band.

[0085] - From a transmission time perspective, a large subcarrier spacing shortens the symbol length in the time domain, and consequently, the slot length shortens, which is advantageous for supporting ultra-low delay services such as URLLC.

[0086] - From a cell size perspective, a longer CP length allows for larger cells to be supported, so a smaller subcarrier spacing allows for relatively larger cells to be supported. In mobile communications, a cell is a concept that refers to the area covered by a single base station.

[0087] The above subcarrier spacing, CP length, etc. are essential information for OFDM transmission and reception. Smooth transmission and reception is possible only when the base station and terminal recognize the subcarrier spacing, CP length, etc. as common values. Table 1 shows the relationship between the subcarrier spacing configuration (μ), subcarrier spacing (f), and CP length supported in the 5G system.

[0088] [Table 1]

[0089]

[0090] Table 2 shows the subcarrier spacing settings for the general CP ( ) not much, each with a different number of symbols per slot ( ), number of slots per frame ( ), number of slots per subframe ( ) is shown.

[0091] [Table 2]

[0092]

[0093] Table 3 shows the subcarrier spacing settings for extended CP ( ) not much, each with a different number of symbols per slot ( ), number of slots per frame ( ), number of slots per subframe ( ) is shown.

[0094] [Table 3]

[0095]

[0096] In the early stages of 5G system deployment, coexistence or dual-mode operation with existing LTE / LTE-A systems is expected. This will allow existing LTE / LTE-A systems to provide stable system operation to terminals, while the 5G system can provide enhanced services to terminals. Therefore, the 5G system's frame structure must at least include the LTE / LTE-A frame structure or essential parameter set (i.e., subcarrier spacing = 15 kHz).

[0097] For example, setting the subcarrier spacing =0 Frame structure (hereinafter referred to as frame structure A) and subcarrier spacing setting = Comparing the frame structure (hereinafter referred to as frame structure B) with frame structure A, frame structure B shows that the subcarrier spacing and RB size are twice as large, and the slot length and symbol length are twice as small. In the case of frame structure B, two slots can constitute one subframe, and 20 subframes can constitute one frame.

[0098] Generalizing the frame structure of a 5G system provides high scalability by ensuring that essential parameters—subcarrier spacing, CP length, and slot length—have integer multiple relationships for each frame structure. Furthermore, a fixed-length subframe of 1 ms can be defined to represent a reference time unit independent of the frame structure.

[0099] The frame structure can be applied to various scenarios. From the perspective of cell size, the longer the CP length, the larger the cell can be supported, so frame structure A can support relatively larger cells than frame structure B. From the perspective of operating frequency band, the larger the subcarrier spacing, the more advantageous it is for phase noise recovery in the high-frequency band, so frame structure B can support relatively higher operating frequencies than frame structure A. From the perspective of service, the shorter the slot length, which is the basic time unit of scheduling, the more advantageous it is for supporting ultra-low-latency services such as URLLC, so frame structure B can be relatively more suitable for URLLC services than frame structure A.

[0100] In the following description of the present disclosure, uplink (UL) may refer to a wireless link through which a terminal transmits data or a control signal to a base station, and downlink (DL) may refer to a wireless link through which a base station transmits data or a control signal to a terminal.

[0101] In the initial access phase when a terminal first accesses the system, the terminal can synchronize downlink time and frequency from a synchronization signal transmitted by a base station through cell search, and obtain a cell identifier (cell ID). Then, the terminal can receive a PBCH using the obtained cell ID, and obtain a master information block (MIB), which is essential system information, from the PBCH. Additionally, the terminal can obtain cell-common transmission and reception-related control information by receiving system information (system information block, SIB) transmitted by the base station. The cell-common transmission and reception-related control information may include random access-related control information, paging-related control information, and common control information for various physical channels.

[0102] The synchronization signal serves as a reference signal for cell search, and subcarrier spacing may be applied to suit channel environments such as phase noise for each frequency band. For data channels or control channels, as described above, different subcarrier spacing may be applied depending on the service type to support various services.

[0103] FIG. 2 is a diagram illustrating an example of a time domain mapping structure and beam sweeping operation of a synchronization signal.

[0104] For the purpose of explanation, the following components may be defined, although they are not limited to the examples below.

[0105] - PSS (primary synchronization signal): PSS is a signal that serves as the basis for DL ​​time / frequency synchronization and provides some cell ID information.

[0106] - SSS (secondary synchronization signal): SSS serves as a reference for DL ​​time / frequency synchronization and provides some remaining information, including the cell ID. Additionally, SSS can serve as a reference signal for PBCH demodulation.

[0107] - PBCH: PBCH provides MIB, which is essential system information required for transmission and reception of data channels and control channels of the terminal. Essential system information may include search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel that transmits system information, and SFN (system frame number), which is a frame-unit index that serves as a timing reference.

[0108] - SS / PBCH block (synchronization signal / PBCH block or SSB(synchronization signal block): An SS / PBCH block consists of N OFDM symbols and is a combination of PSS, SSS, PBCH, etc. In a system where beam sweeping technology is applied, an SS / PBCH block is the minimum unit to which beam sweeping is applied. In a 5G system, N can be 4. A base station can transmit up to L SS / PBCH blocks, and the L SS / PBCH blocks are mapped within a half frame (0.5 ms). And the L SS / PBCH blocks are periodically repeated in units of a predetermined period P. The period P can be notified to the terminal by the base station through signaling. If there is no separate signaling for the period P, the terminal applies a pre-agreed default value.

[0109] Referring to FIG. 2, an example of applying beam sweeping to SS / PBCH block units over time is illustrated. In the example of FIG. 2, terminal 1 (205) can receive an SS / PBCH block using a beam radiated in the direction of #d0 (203) by beamforming applied to SS / PBCH block #0 at time t1 (201). Terminal 2 (206) can receive an SS / PBCH block using a beam radiated in the direction of #d4 (204) by beamforming applied to SS / PBCH block #4 at time t2 (202). The terminal can obtain an optimal synchronization signal through a beam radiated from the base station in the direction where the terminal is located. For example, terminal 1 (205) may have difficulty obtaining time / frequency synchronization and essential system information from an SS / PBCH block through a beam radiated in the direction of #d4, which is far from the location of terminal 1.

[0110] In addition to the initial connection procedure, the UE may also receive SS / PBCH blocks to determine whether the radio link quality of the current cell is maintained at a certain level. Furthermore, during a handover procedure, in which the UE moves from the current cell to a neighboring cell, the UE may receive SS / PBCH blocks from the neighboring cell to determine the radio link quality of the neighboring cell and obtain time / frequency synchronization with the neighboring cell.

[0111] After the terminal acquires MIB and system information from the base station through the initial access procedure, the terminal can perform a random access procedure to transition the link with the base station to a connected state (or RRC_CONNECTED state). Upon completion of the random access procedure, the terminal transitions to a connected state, enabling one-to-one communication between the base station and the terminal. The random access procedure is described in detail below with reference to FIG. 3.

[0112] FIG. 3 is a diagram illustrating an example of a random access procedure according to one embodiment of the present disclosure.

[0113] Referring to FIG. 3, as a first step (310) of a random access procedure, a terminal may transmit a random access preamble to a base station. The random access preamble, which is the first transmission message of the terminal in the random access procedure, may be referred to as message 1. The base station may measure a transmission delay value between the terminal and the base station from the random access preamble and synchronize uplink. At this time, the terminal may arbitrarily select which random access preamble to use within a random access preamble set given in advance by system information. In addition, the initial transmission power of the random access preamble may be determined according to the path loss between the terminal and the base station measured by the terminal. In addition, the terminal may determine the transmission beam direction of the random access preamble from the synchronization signal received from the base station and transmit the random access preamble.

[0114] In the second step (320), the base station may transmit an uplink transmission timing adjustment command to the terminal based on the transmission delay value measured from the random access preamble received in the first step (310). Furthermore, the base station may transmit uplink resources and power control commands to be used by the terminal as scheduling information. The scheduling information may include control information regarding the terminal's uplink transmission beam.

[0115] If the terminal does not receive the random access response (RAR, message 2), which is scheduling information for message 3, from the base station within a predetermined time in the second step (320), the first step (310) can be performed again. If the first step (310) is performed again, the terminal can increase the probability of the base station receiving the random access preamble by transmitting the random access preamble with the transmission power increased by a predetermined step (power ramping).

[0116] In the third step (330), the terminal can transmit uplink data including its terminal ID (i.e., message 3) to the base station through an uplink data channel (physical uplink shared channel, PUSCH) using the uplink resources allocated in the second step (320). The transmission timing of the uplink data channel for transmitting message 3 may follow the timing control command received from the base station in the second step (320). In addition, the transmission power of the uplink data channel for transmitting message 3 may be determined in consideration of the power control command received from the base station in the second step (320) and the power ramping value of the random access preamble. The uplink data channel for transmitting message 3 may mean the first uplink data signal that the terminal transmits to the base station after transmitting the random access preamble.

[0117] In step 4 (340), if the base station determines that the terminal has performed random access without collision with other terminals, the base station can transmit data (message 4) including the ID of the terminal that transmitted uplink data in step 3 (330) to the terminal. If the terminal receives the signal transmitted by the base station in step 4 (340) from the base station, the terminal can determine that the random access has been successful. In addition, the terminal can transmit HARQ-ACK information indicating whether message 4 has been successfully received to the base station through an uplink control channel (physical uplink control channel, PUCCH).

[0118] If the data transmitted by the terminal in step 3 (330) collides with data from another terminal, causing the base station to fail to receive a data signal from the terminal, the base station may not transmit any more data to the terminal. Accordingly, if the terminal fails to receive the data transmitted from the base station in step 4 (340) within a certain period of time, it may determine that the random access procedure has failed and may perform the procedure again from step 1 (310).

[0119] Upon successful completion of the random access procedure, the terminal transitions to the connected state (RRC_CONNECTED state), enabling one-to-one communication between the base station and the terminal. The base station receives UE capability information from the connected terminal and can adjust scheduling based on the UE capability information. Through UE capability information, the terminal can inform the base station whether it supports a given function and the maximum allowable value of the function supported by the terminal. Therefore, the UE capability information reported by each terminal to the base station may have different values ​​for each terminal.

[0120] For example, a terminal may report terminal capability information to a base station, including at least a portion of the following control information as terminal capability information. Of course, the following examples are not limited thereto.

[0121] - Control information related to frequency bands supported by the terminal

[0122] - Control information related to channel bandwidth supported by the terminal

[0123] - Control information related to the maximum modulation method supported by the terminal

[0124] - Control information related to the maximum number of beams supported by the terminal

[0125] - Control information related to the maximum number of layers supported by the terminal

[0126] - Control information related to reporting channel state information supported by the terminal

[0127] - Control information on whether the terminal supports frequency hopping

[0128] - Bandwidth-related control information when supporting carrier aggregation (CA)

[0129] - Control information on whether cross carrier scheduling is supported when carrier aggregation is supported.

[0130] Figure 4 is a diagram showing an example of a procedure in which a terminal reports terminal capability information to a base station.

[0131] Referring to FIG. 4, at step 410, the base station (402) can transmit a terminal capability information request message to the terminal (401). In response to the terminal capability information request from the base station, the terminal transmits terminal capability information to the base station at step 420.

[0132] Through the aforementioned process, a terminal connected to a base station is considered a connected terminal, capable of one-to-one communication. Conversely, a terminal that is not connected is considered an idle terminal (RRC_IDLE state). The behavior of an idle terminal can be categorized as follows. Of course, the following examples are not limited to this example.

[0133] - Operates a terminal-specific DRX (discontinuous reception) cycle set by the upper layer.

[0134] - Action to receive paging messages from the core network

[0135] - Obtain system information

[0136] - Measurement operations related to surrounding cells and cell reselection

[0137] In 5G systems, a new state called the inactive state (RRC_INACTIVE state) has been defined to reduce the energy and time consumed by a terminal's initial access. Inactive terminals can perform the following actions in addition to those performed by idle terminals. These actions are not limited to the examples below.

[0138] - Storage of AS (access stratum) information required for cell access

[0139] - Terminal-specific DRX cycle operation set by the RRC layer

[0140] - Setting up and periodically updating an RNA (RAN-based notification area) that can be used during handover by the RRC layer.

[0141] - Monitoring RAN-based paging messages transmitted via I-RNTI (inactive radio network temporary identifier)

[0142] Below, a scheduling method for a base station to transmit downlink data to a terminal or instruct the terminal to transmit uplink data is described.

[0143] Downlink control information (DCI) is control information transmitted from a base station to a terminal via the downlink. It may include downlink data scheduling information or uplink data scheduling information for a given terminal. Typically, the base station independently channel-codes DCI for each terminal and then transmits it to each terminal via a physical downlink control channel (PDCCH).

[0144] The base station can operate by applying a predetermined DCI format according to the purpose, such as whether it is scheduling information for downlink data (downlink assignment), scheduling information for uplink data (uplink grant), or DCI for power control, for the terminal to be scheduled.

[0145] A base station can transmit downlink data to a terminal via a physical downlink shared channel (PDSCH) for downlink data transmission. Scheduling information, such as the specific mapping location in the time and frequency domains of the PDSCH, modulation scheme, HARQ-related control information, and power control information, can be provided by the base station to the terminal via DCI related to downlink data scheduling information among the DCIs transmitted via the PDCCH.

[0146] A terminal can transmit uplink data to a base station via the PUSCH. Scheduling information, such as the specific mapping location in the time and frequency domains of the PUSCH, modulation scheme, HARQ-related control information, and power control information, can be provided to the terminal by the base station via DCI related to uplink data scheduling information, among the DCIs transmitted via the PDCCH.

[0147] The time-frequency resources to which the PDCCH is mapped are called control resource sets (CORESETs). A CORESET can be configured for all or part of the frequency resources of the bandwidth supported by the UE in the frequency domain. In the time domain, it can be configured with one or more OFDM symbols, which can be defined as the CORESET length (control resource set duration). The base station can configure one or more CORESETs to the UE through higher layer signaling (e.g., at least one of system information, MIB, and RRC signaling). Configuring a CORESET for the UE may mean providing information such as the CORESET identifier, the frequency location of the CORESET, and the symbol length of the CORESET. The information that the base station provides to the UE to configure the CORESET may follow the contents described in 3GPP TS 38.331.

[0148] CORESET is in the frequency domain It can be composed of RBs and in the time domain It can be composed of symbols. The NR PDCCH can be composed of one or more CCEs (control channel elements). One CCE can be composed of six REGs (resource element groups), and a REG can be defined as one RB during one OFDM symbol. Within one CORESET, REGs can be indexed in time-first order, starting with REG index 0 from the first OFDM symbol of the CORESET, the lowest RB.

[0149] Interleaved and non-interleaved transmission methods for PDCCH can be supported. The base station can configure whether to use interleaved or non-interleaved transmission for each CORESET to the terminal through upper layer signaling. Interleaving can be performed in units of REG bundles. A REG bundle can be defined as a set of one or more REGs. The terminal can determine the CCE-to-REG mapping method in the corresponding CORESET based on whether to use interleaved or non-interleaved transmission as configured by the base station, as shown in Table 4 below.

[0150] [Table 4]

[0151]

[0152] The base station can inform the terminal of configuration information such as whether the PDCCH is mapped to which symbol within a slot and the transmission cycle through signaling.

[0153] The search space of the PDCCH is described as follows. The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs can be used for link adaptation of the downlink control channel. For example, when AL=L, a single downlink control channel can be transmitted through L CCEs. The UE performs blind decoding to detect a signal without knowing information about the downlink control channel, and for this purpose, a search space representing a set of CCEs can be defined. The search space is a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode at a given aggregation level, and since there are various aggregation levels that create a single bundle with 1, 2, 4, 8, or 16 CCEs, the UE can have multiple search spaces. A search space set can be defined as the set of search spaces at all established aggregation levels.

[0154] Search spaces can be categorized into a common search space (CSS) and a UE-specific search space (USS). A certain group of UEs, or all UEs, can scan the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling for system information or paging messages. For example, a UE can receive scheduling allocation information for a PDSCH for system information reception by scanning the common search space of the PDCCH. In the case of the common search space, since a certain group of UEs, or all UEs, must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. UE-specific scheduling allocation information for a PDSCH or PUSCH can be received by scanning the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the UE identifier and various system parameters.

[0155] The base station can set configuration information for the search space of the PDCCH to the terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can set the number of PDCCH candidates in each aggregation level L, the monitoring period for the search space, the monitoring time point (occasion) for each symbol in the slot for the search space, the search space type (common search space or terminal-specific search space), the combination of the DCI format and RNTI (radio network temporary identifier) ​​to be monitored in the corresponding search space, the CORESET index to be monitored for the search space, etc. to the terminal. For example, the parameters for the search space for the PDCCH can follow the contents described in 3GPP TS 38.331. Depending on the configuration information, the base station can set one or more search space sets to the terminal. According to one embodiment of the present disclosure, the base station can set search space set 1 and search space set 2 to the terminal. In search space set 1, the terminal may be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and in search space set 2, the terminal may be configured to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.

[0156] According to the configuration information, one or more search space sets may exist in a common search space or a terminal-specific search space. For example, search space set #1 and search space set #2 may be configured as a common search space, and search space set #3 and search space set #4 may be configured as terminal-specific search spaces.

[0157] In a common search space, a terminal can monitor the following combinations of DCI formats and RNTIs, although these are not limited to the following examples.

[0158] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0159] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0160] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0161] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0162] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0163] In a terminal-specific search space, a terminal can monitor the following combinations of DCI formats and RNTIs, although these are not limited to the following examples.

[0164] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0165] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0166] The above-mentioned RNTIs may follow the following definitions and uses:

[0167] - C-RNTI (cell RNTI): For terminal-specific PDSCH or PUSCH scheduling purposes.

[0168] - TC-RNTI (temporary cell RNTI): For terminal-specific PDSCH scheduling purposes

[0169] - CS-RNTI (configured scheduling RNTI): Used for terminal-specific PDSCH scheduling that is set semi-statically.

[0170] - RA-RNTI (random access RNTI): Used for PDSCH scheduling in the random access phase.

[0171] - P-RNTI (paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0172] - SI-RNTI (system information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0173] - INT-RNTI (interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0174] - TPC-PUSCH-RNTI (transmit power control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0175] - TPC-PUCCH-RNTI (transmit power control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0176] - TPC-SRS-RNTI (transmit power control for SRS RNTI): Used to indicate power control commands for SRS.

[0177] The DCI formats described above can follow the definitions shown in Table 5 below.

[0178] [Table 5]

[0179]

[0180] CORESET p, the search space of aggregation level L in the search space set s can be expressed as the following mathematical formula.

[0181] [Mathematical Formula 1]

[0182]

[0183] The value can be 0 for a common search space.

[0184] In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's ID (C-RNTI or ID set to the terminal by the base station) and the time index.

[0185] As described above, to achieve ultra-high-speed data services reaching several Gbps in 5G systems, ultra-wide bandwidth signal transmission and reception of tens to hundreds of MHz or even several GHz may be supported. Ultra-wide bandwidth signal transmission and reception may be supported through a single component carrier (CC) or through carrier aggregation technology that combines multiple component carriers. When a mobile communication service provider is unable to secure a frequency with sufficient bandwidth for ultra-high-speed data services through a single component carrier, carrier aggregation technology can increase the total frequency bandwidth by combining individual component carriers with relatively small bandwidths, thereby enabling ultra-high-speed data services.

[0186] 5G systems are designed and developed for a wide range of use cases. In addition to standby time, reliability, and availability, device energy efficiency is crucial in 5G systems. 5G devices require weekly or daily charging, depending on individual usage. Typically, 5G devices consume tens of milliwatts (mW) when idle or inactive, and hundreds of mW when connected. Designing for extended battery life is essential not only for a better user experience but also for improving energy efficiency. Energy efficiency is even more critical for devices without a continuous energy source, such as those using small rechargeable or single coin-cell batteries. Sensors and actuators will be widely deployed for 5G use cases, including monitoring, measurement, and charging. Typically, the batteries for these sensors and actuators are non-rechargeable and will require a battery life of at least several years. Wearables include smartwatches, rings, eHealth devices, and medical monitoring devices, but these devices typically struggle to maintain a battery life of one to two weeks, depending on usage.

[0187] One way to reduce power consumption in 5G terminals is to operate in DRX mode. DRX-enabled terminals are activated periodically, transmitting and receiving information only during specific periods. The reduction in power consumption depends on the length of the active period, such as the paging cycle. To meet battery life requirements, it is expected that extended discontinuous reception (eDRX) cycles with higher values ​​will be used.

[0188] However, using eDRX cycles may not be suitable for low-latency services because long battery life relies on long latency. For example, in a fire detection and suppression use case, fire shutters must close and sprinklers must be activated by actuators within 1-2 seconds of a fire being detected by a sensor. Therefore, in latency-critical use cases, the traditionally high-value eDRX cycles may not be able to meet the latency requirements, making eDRX unsuitable.

[0189] 5G terminals need to wake up periodically once per DRX cycle to check if there is data to be received, which can cause unnecessary power consumption during periods without signaling or data traffic. To solve this problem, if the terminal could wake up only when it needs to be activated, such as when there is data that the terminal needs to receive, such as paging information, power consumption could be drastically reduced. This can be achieved by using a wake-up receiver (WUR) that can monitor the wake-up signal (WUS) with ultra-low power, thereby turning on (or triggering) the main radio (which can be understood as a signal transmission and reception device that can perform data communication using existing NR radio devices or cellular communication) only when data transmission and reception are required.

[0190] FIG. 5 is a diagram illustrating an example of an operation in which a base station instructs a terminal with WUR to switch to the main radio state through WUS.

[0191] Referring to FIG. 5, when a base station transmits a WUS (501) corresponding to ON or OFF to a terminal (UE), the terminal can receive the WUS (501) using a WUR (502). Here, the WUR may be a low power WUR. Depending on whether the received signal is ON or OFF information, the terminal can trigger (503) the main radio (504) in the OFF or ON state to wake it up or turn it off, respectively. In some cases, the terminal may not completely turn off the main radio (504), but may also turn off most of the components of the main radio and set it to a deep sleep state in which only essential components such as an internal clock and memory operate.

[0192] If data traffic (505) to be transmitted from the base station to the terminal occurs and a WUS corresponding to ON is transmitted from the base station to the terminal, the main radio becomes ON (506), and the terminal can receive the data transmitted by the base station through the main radio, not the WUR. Since the power consumption for monitoring the WUS depends on the WUS design and the hardware module of the WUR used for signal detection and processing, it can be expected that the benefits of utilizing WUS and WUR will be maximized, especially for power-sensitive and small form factor devices including IoT use cases (such as industrial sensors and controllers) and wearables.

[0193] When designing a wake-up receiver capable of receiving WUS, a variety of wake-up receivers can be designed based on the waveform or modulation method of the wake-up signal and the corresponding reception method. For example, if the WUS waveform is designed using on-off keying (OOK), the terminal (or WUR) can determine the encoded bit information transmitted from the base station through a receiver equipped with an envelope detector that measures the envelope of the signal's reception power. Since signal phase information, etc., is unnecessary during the signal reception process, a phase-locked loop (PLL) for signal phase synchronization and a fast Fourier transform (FFT) module typically required in OFDM receivers are also not required. Therefore, the receiver structure is relatively simple, allowing the terminal (or WUR) to operate using low power to receive WUS and reduce the terminal's overall power consumption. However, coverage is limited compared to other channels in existing 5G systems due to attenuation caused by the wireless channel, and significant resources must be consumed in the time dimension to ensure reception performance compared to OFDM-based signals. In the following description, a receiver that determines the information to be transmitted based on the envelope measurement of the received power of the signal is called a low power receiver A (WUR-A).

[0194] Another method is to utilize the existing OFDM-based modulation method as another WUS waveform. In the IFFT (inverse fast Fourier transform) module used in OFDM-based signal transmission, the sequence corresponding to the WUS information to be transmitted is mapped to the subcarrier allocated for WUS transmission, and the WUS can be generated in the same way as the existing OFDM-based synchronization signal and reference signal. In this case, if a different sequence is transmitted depending on the type of WUS information to be transmitted, information can be transmitted to the terminal through the sequence. Alternatively, a method of transmitting information based on whether a specific sequence has been transmitted or not can also be considered. The receiver receiving the WUS can determine the presence of WUS reception and the operation of the main radio using a cross-correlator in the time dimension without an FFT module, and depending on the implementation, if the FFT module is installed in the WUR, the above operation can be performed in the frequency dimension through the FFT module. Unlike OOK-based WUS, OFDM-based WUS requires in-phase and quadrature branch (IQ branch) and PLL to receive complex information. However, components with lower performance but lower power consumption than those mounted on the main radio can be used. In addition, other components can be used with relatively low power consumption at the expense of performance, so that the power consumed through them can be reduced compared to the main radio. Moreover, when receiving WUS using a cross-correlator in the time dimension, WUS can be received without an FFT module, which can further reduce power consumption. A receiver that determines transmitted information based on receiving complex signals in the baseband in the time dimension or frequency dimension using IQ branch and PLL is named Low Power Receiver B (WUR-B).

[0195] Assuming that WUR is activated for the same amount of time to receive WUS, the average power required for WUR-B is bound to be relatively higher than that of WUR-A. Therefore, in terms of the overall power reduction gain of the terminal, WUR-A is higher. However, when comparing in terms of WUS reception capability, that is, in terms of coverage, WUR-B has a higher performance than WUR-A, so it can reliably receive WUS transmitted by the base station over a wider area. Therefore, depending on the characteristics of the terminal, such as the purpose of use, power reduction gain, and mobility, there are cases where WUR-A is advantageous, and cases where WUR-B is advantageous. For example, in the case of IoT devices that require extremely low power consumption due to the installation of a semi-permanent battery, it is advantageous to install WUR-A, whereas in the case of terminals such as smartphones that require stable operation in environments with high mobility, WUR-B is advantageous. As described above, different WURs can be installed according to the characteristics of the terminal.

[0196] Therefore, if a base station supports a WUS that can only be received with either a WUR-A or WUR-B receiver structure, the WUR implementation of the terminal and the benefits that can be obtained are limited. On the other hand, a method in which the base station supports both a WUS that can be received with WUR-A and a WUS that can be received with WUR-B can be considered. However, this requires that the base station know which type of WUR is installed in each terminal in order to transmit the WUS corresponding to the WUR of each terminal. If the base station does not know this information, it must transmit both types of WUS to wake up a terminal or a group of terminals. This may result in a separate implementation for transmitting different types of WUS and more resource consumption.

[0197] In other words, from the base station's perspective, it is more advantageous to transmit a single type of WUS using the same resource than to generate multiple types of WUS, map them to separate resources, and transmit them. Therefore, considering both the convenience of the base station and the freedom of WUR implementation at the terminal, it is helpful to design the WUS so that both terminals with WUR-A and terminals with WUR-B can receive the same type of WUS.

[0198] When a base station transmits a WUS to save power for a terminal, related operations, including the terminal's WUS reception, may be determined according to specific conditions. That is, the terminal may require specific conditions for WUS reception through a WUR, and these conditions may vary depending on the terminal's RRC state and the terminal's WUR type (e.g., WUR-A or WUR-B).

[0199] Hereinafter, through specific embodiments, the conditions required for the terminal to operate WUR, including receiving WUS, depending on the RRC state of the terminal or the type of WUR, and the operation of the terminal depending on whether the conditions are met will be specifically described. In the following description, WUS is a signal that can be commonly received through WUR-A and WUR-B receivers regardless of the type of WUR, and to express that WUS is a signal that can be received with low power to save power of the terminal, it is called LP-WUS (Low Power Wake-up signal), and WUR is called LP-WUR (Low Power Wake-up receiver).

[0200] The base station or terminal described in the present disclosure may be replaced with any device that transmits (or receives) LP-WUS designed for the same purpose. For example, the entity transmitting the LP-WUS may be another terminal, and the entity receiving the LP-WUS may also be considered any device that receives the LP-WUS, without being limited to the terminal. Accordingly, the design includes not only the LP-WUS in the downlink transmitted from the base station to the terminal, but also the uplink LP-WUS transmitted from the terminal to the base station, and the sidelink LP-WUS transmitted from the terminal to another terminal.

[0201] Before explaining the LP-WUS-related operations of the base station and terminal in detail, the operation of a terminal without an LP-WUS function or a terminal with an LP-WUS function but not using the function will be explained through FIGS. 6a and 6b.

[0202] FIG. 6a illustrates an example of operations performed by a base station of a terminal in RRC IDLE and INACTIVE states to receive a paging message transmitted by the base station. The figure illustrates a terminal having a PEI (Paging Early Indication) monitoring function, but whether to monitor PEI and implement the PEI function may vary depending on the implementation of the terminal. In addition, a terminal in RRC IDLE or INACTIVE states operates in DRX, which periodically turns ON / OFF the terminal's reception operation to reduce power consumption. The DRX applied when in RRC IDLE or INACTIVE states is called i-DRX, and the corresponding cycle may be referred to as an i-DRX cycle. If a longer DRX cycle is desired, eDRX may be supported depending on the capability of the terminal.

[0203] In Figure 601, the terminal determines the i-DRX cycle and the location of the Paging Occasion (PO) that the terminal should monitor based on the system information of the base station. The location of the PO is specified in the standard in connection with the SSB received by the terminal, and the specific location of the PO, such as the radio frame, is determined according to the group to which the terminal belongs. Furthermore, it can be assumed that terminals belonging to the same group can receive necessary information from the same PO. The terminal can determine the location of a specific PO based on its own unique ID and acquired system information, which is derived based on the formula specified in the standard. If the terminal supports the PEI monitoring function, it can determine the location to monitor the PEI along with the location of the PO. The terminal can receive the PDCCH CRC-scrambled with the P-RNTI in the PO and the corresponding PDSCH. The terminal receiving the PEI receives the PDCCH CRC-scrambled with the pei-RNTI at the time of receiving the pei associated with specific POs. In the following description, a PDCCH CRC-scrambled with P-RNTI is called a paging PDCCH, and a PDCCH CRC-scrambled with pei-RNTI at a point in time (i.e., a PDCCH transmitting DCI format 2_7) is called a PEI.

[0204] In the 602 process, PEI must be monitored for each i-DRX cycle to determine whether there is paging information that the terminal should receive. However, a terminal with PEI monitoring function consumes power to receive the corresponding PDCCH for each i-DRX cycle.

[0205] This is also the reason for introducing LP-WUS. Even if the terminal's receiver, i.e., MR, can remain in a sleeping state until monitoring the PDCCH, it cannot maintain deep sleep because it must receive the PDCCH for every i-DRX cycle. The deeper the sleep of the terminal, that is, the closer the power consumption of the hardware constituting the terminal is to 0, the longer it takes for the terminal to come out of the sleeping state and prepare to receive a specific signal, and the additional power consumption required to turn the hardware that was turned off from the OFF state to the ON state is also considerably large. Therefore, in order to save power by maintaining the terminal in a deeper sleep state (e.g., ultra deep sleep state, UDS), it is important to reduce the frequency with which most of the hardware constituting the terminal wakes up to receive a specific signal. At this time, receiving LP-WUS through LP-WUR can significantly reduce power consumption by reducing the frequency with which other hardware in the terminal wakes up.

[0206] At this time, a terminal without a PEI monitoring function skips steps 602 to 603 and monitors the paging PDCCH in every i-DRX cycle in step 604 to determine whether there is a paging message related to the terminal or whether a paging PDCCH that the terminal should receive is arriving.

[0207] A terminal with PEI monitoring function determines whether there is an instruction for its subgroup through PEI in step 603. At this time, a subgroup is a concept that further groups terminals belonging to the same group that monitor the same PO. When the terminal acquires system information in step 601, it also acquires information for determining its subgroup and determines the subgroup based on the formula specified in the standard. If the DCI field corresponding to the subgroup to which it belongs indicates '1' in step 603, it is considered that the subgroup to which it belongs has indicated that it should receive a paging PDCCH from the PO, and step 604 is performed. Otherwise, it remains in sleep mode and repeats step 602 from the next cycle.

[0208] A UE that has been instructed to receive a paging PDCCH through PEI receives the paging PDCCH through process 604. The PDCCH can be used for two main purposes: scheduling a PDSCH containing the paging message that the UE must receive, and transmitting a short message containing information on the PDCCH. The short message may include information indicating whether to update the base station's system information, or may include urgent information such as the Public Warning System (PWS). UEs that receive the short message through process 604 skip processes 605 and 606 and receive necessary system information, including SIB1, through process 607. If the UE maintains the RRC IDLE or INACTIVE state, the operation of monitoring PEI (if the UE supports the monitoring function) or PO is repeated through process 602 in the next i-DRX cycle.

[0209] When the paging PDCCH is used to schedule a PDSCH containing a paging message, the paging message is received on the PDSCH through step 605, and then the UE checks whether there is a paging message corresponding to the UE through step 606. Since the paging operation of the UE is performed based on group-based instructions, there may be cases where the UE wakes up to receive a paging message that is not relevant to the UE. If there is only information not relevant to the UE, the UE returns to step 602 and repeats the operation of monitoring PEI (if the UE supports the monitoring function) or PO in the next i-DRX cycle.

[0210] If a paging message is available, the corresponding information can be obtained. For example, information can be transmitted instructing the terminal to transition to the RRC CONNECTED state. Upon obtaining this information, the terminal can perform subsequent actions, such as transmitting a PRACH to the base station to initiate the transition to the RRC CONNECTED state.

[0211] FIG. 6b illustrates an example of an operation performed by a terminal in an RRC CONNECTED state to receive a PDCCH transmitted by a base station in a situation where DRX is operating. FIG. 6b basically represents an operation of a terminal receiving DCI format 2_6 in a situation where C-DRX (Continuous DRX) is configured to basically save power of a terminal in an RRC CONNECTED state. At this time, C-DRX refers to DRX configured for a terminal in an RRC CONNECTED state, and the corresponding DRX cycle is called a C-DRX cycle. In addition, DCI format 2_6 is a DCI that transmits a PDCCH CRC-scrambled with ps-RNTI and indicates whether a specific terminal performs PDCCH monitoring in the ON cycle (ON duration) of the next C-DRX. At this time, a terminal in which C-DRX is configured can save power by performing PDCCH monitoring only in the ON cycle and not performing PDCCH monitoring during the OFF cycle. That is, DCI format 2_6 serves to inform whether there is a PDCCH that the terminal should monitor during the next ON cycle.

[0212] Among RRC CONNECTED terminals, terminals capable of receiving DCI format 2_6 report the minimum time gap to the base station in step 608. The value is set to receive DCI format 2_6 before the ON duration. The terminal starts a timer called drx-onDurationTimer when the ON duration capable of performing PDCCH monitoring starts, and before the timer starts, the terminal reports the minimum gap required by the terminal in slot units to receive DCI format 2_6. In other words, the terminal does not expect to receive DCI format 2_6 before the number of slots reported as the minimum time gap from the time when the timer called drx-onDurationTimer starts to run.

[0213] In process 609, the terminal obtains C-DRX-related settings, and accordingly, obtains information such as in which section DCI format 2_6 should be received, and from when and at what cycle the ON duration of C-DRX operates. In addition, since DCI format 2_6 is transmitted as a PDCCH that multiple terminals see together, it is possible to determine which part of the DCI field applies to the terminal based on the information obtained from the base station. At this time, information from the base station is obtained through RRC signaling, etc.

[0214] In step 610, DCI format 2_6 is monitored based on the information obtained, and if the field indicating wake-up in DCI format 2_6 in step 611 is marked with a value of '1', PDCCH is monitored in the next on duration through step 612. At this time, the timer called drx-onDurationTimer is started to operate as described above. If the field indicating wake-up in step 611 is marked with a value of '0', step 610 is repeated.

[0215] In step 612, the terminal monitors the PDCCH until the drx-onDurationTimer expires. If the terminal does not receive the PDCCH it should receive before the timer expires in step 613, it returns to step 610 and repeats the operation of monitoring DCI format 2_6 in the next C-DRX.

[0216] If a PDCCH for scheduling a UL or DL ​​channel of the terminal is received before the timer expires in step 613, the terminal may extend the ON duration of the terminal by operating the drx-InactivityTimer to secure time to process the scheduled PDSCH or PUSCH. This can be extended continuously if the base station continues to send PDCCH or the like. If the timer expires thereafter, the terminal returns to step 610 and repeats the operation of monitoring DCI format 2_6 in the next C-DRX.

[0217] If the terminal does not have the function of monitoring DCI format 2_6, steps 610 and 611 must be skipped and PDCCH monitoring must be performed for the period corresponding to the ON duration for each C-DRX cycle through step 612.

[0218] In the present disclosure, LP-WUS monitoring may be performed by a separate receiver LP-WUR of a terminal, or by activating only a minimum number of functions required for LP-WUS monitoring in an existing receiver. In the following description, LP-WUR performing LP-WUS monitoring includes both performing LP-WUS monitoring in a separate receiver equipped for the purpose of LP-WUS reception and performing LP-WUS monitoring in an existing receiver that receives a different channel.

[0219] <Example 1>

[0220] The first embodiment of the present disclosure describes the overall procedures and operations of a base station and a terminal supporting LP-WUS operation. Specifically, the process of the base station activating and deactivating LP-WUS transmission and the related operations of the terminal are described. All procedures in the following description are described based on LP-WUS transmitted from the base station to the terminal in the downlink. However, as mentioned above, the entities transmitting and receiving LP-WUS are not limited to the base station and the terminal, respectively. Even if the entities are changed, the corresponding procedures and operations of the entities can be applied equally.

[0221] Before explaining the procedure in detail, we will explain the signals transmitted by the base station supporting LP-WUS, which are related to the reception and operation of LP-WUS by the terminal. Regardless of the RRC state of the terminal, the terminal is required to receive a synchronization signal to periodically synchronize with the base station to ensure smooth communication and to periodically measure the channel condition of the cell to determine if communication is possible when necessary. Among the terminals that can receive LP-WUS, there may be a terminal with LP-WUR that cannot receive signals such as PSS and SSS, which are used by the main radio (MR) for synchronization or channel quality measurement. Among the various WUR types described above, the terminal with WUR-A falls into this category. In order for the terminal to stably receive LP-WUS, a process such as synchronization with the base station may be required. However, if the MR is turned ON every time this process is performed, the power saving effect is reduced. Therefore, in order to save power for terminals with LP-WUR that cannot receive existing signals, the base station can transmit a separate synchronization signal that can also be received by the terminals. In the following description, this synchronization signal is referred to as LP-SS (Low Power Synchronization Signal). At this time, LP-SS is used not only to synchronize before LP-WUR receives LP-WUS, but also to measure the status of the channel. For example, IDLE and INACTIVE terminals require serving cell channel measurement for each DRX cycle, and the channel measurement that was previously based on SSS can be performed based on LP-SS. At this time, synchronization and channel measurement based on LP-SS may not be limited to LP-WUR that cannot receive existing PSS or SSS.That is, LP-WUR, such as WUR-B, which can receive signals that existing MRs use for the same purpose, such as PSS or SSS, can additionally use LP-SS for synchronization purposes or channel measurement purposes. However, a terminal with a WUR-B type LP-WUR can also use LP-SS only if the LP-SS is designed to be a signal that can be received by any type of LP-WUR, like LP-WUS described previously. That is, LP-SS may be supported to be received regardless of the type of WUR, or may be supported only for a specific WUR type (WUR-A in this disclosure). Furthermore, considering that the main purpose of LP-SS is synchronization of LP-WUR and channel measurement through LP-WUR, it may be supported for only some purposes for specific types. For example, in the case of WUR-B, since it can receive existing signals, there is no need to receive LP-SS separately. However, if the band where the existing PSS and SSS are transmitted is different from the band where LP-WUS and LP-SS are transmitted, synchronization through LP-SS can be performed to better synchronize in the corresponding frequency band before receiving LP-WUS. However, when measuring the serving cell of a terminal with WUR-B, if it is required to be based on SSS, similar to how the existing terminal measures based on MR, WUR-B can only perform synchronization based on LP-SS and cannot utilize LP-SS for the purpose of measuring the serving cell and determining whether the cell channel is suitable. On the other hand, in the case of a terminal with WUR-A, the serving cell measurement requirement is set based on LP-SS, so that not only synchronization but also serving cell measurement can be performed using LP-SS. As explained, depending on the type of LP-WUR that the terminal has, the signal that it receives to perform a specific function may vary.

[0222] Figure 7 is a drawing illustrating an example of a base station's status and status change procedure depending on whether LP-WUS transmission is performed.

[0223] Referring to FIG. 7, a base station in state 701 is a base station that can support LP-WUS or both LP-WUS and LP-SS, but is not transmitting LP-WUS and LP-SS. However, the base station may be transmitting other signals, including synchronization signals such as PSS and SSS, to support existing operations such as SSB reception, PDCCH reception, and system operation acquisition other than LP-WUS reception by the terminal.

[0224] A base station in state 701 may be a base station that was transmitting LP-WUS (and LP-SS) and then disabled the function, or may have never enabled LP-WUS and LP-SS transmission functions in the first place. In addition, if a base station introduces a function to periodically limit signal transmission to save power, that is, when performing Discontinuous Transmission (DTX) operation such as DRX operation, it may not transmit on certain channels in the OFF state, and in this case, LP-WUS and LP-SS transmission may not occur.

[0225] At 702, the base station determines whether to transmit the corresponding signals for LP-WUS and LP-SS transmission. This can be done by the base station determining in which situation to transmit LP-WUS and LP-SS in the implementation, or when the base station performs DTX operation, it can operate so that the LP-WUS and LP-SS transmission functions are also activated (703) while switching from OFF to ON.

[0226] Regardless of the LP-WUS and LP-SS transmission status of the base station, the network continuously stores whether the terminal is in the capability and may know in which area the terminal is located. Therefore, it can determine how many terminals in a specific area have LP-WUS or LP-SS reception capability, and whether a specific base station is suitable for activating the LP-WUS and LP-SS functions. In addition, since LP-WUS and LP-SS transmission require additional resource consumption, when the resource utilization rate due to other channel transmission is high, the LP-WUS and LP-SS transmission functions may be disabled and not transmitted. However, when communication resources are available, a decision can be made to activate the LP-WUS and LP-SS transmission functions (703). If it is decided not to activate the LP-WUS and LP-SS transmission functions for any reason, including the examples described above, the base station will remain in state 701, and if it is decided to activate them, the base station will go through state 703. In this way, the activation of LP-WUS and LP-SS functions by the base station may depend on the implementation of the base station, or may operate by setting certain criteria and activating them when (or not) the criteria are met. The criteria may be determined by the amount of resources that the base station can operate, the number of terminals that can receive LP-WUS, etc., and may be determined in relation to the power saving function of the base station, such as when the base station is not in an OFF state. Combinations of each example may also be considered, and the criteria for the base station to activate LP-WUS and LP-SS are not limited to the examples above.

[0227] Also, in state 701, the base station does not transmit both LP-WUS and LP-SS, i.e., does not fully support the LP-WUS function. The base station can activate both LP-WUS and LP-SS in state 703 based on the judgment in process 702. On the other hand, the base station can also be activated by transmitting only LP-WUS without transmitting LP-SS. For example, in the case of a terminal with WUR-B, since it has the ability to receive PSS and SSS included in the existing SSB signal, necessary processes such as synchronization and serving cell channel measurement can be performed without receiving LP-SS. Or, when the LP-WUS function is activated only for an RRC CONNECTED terminal, a separate signal for synchronization of LP-WUR may not be required because the sleep time of the MR or the cycle for receiving LP-WUS is not as long as that of terminals in RRC IDLE and INACTIVE states. This means that the base station does not necessarily need to transmit LP-SS to support the LP-WUS function of the corresponding terminals. In this case, the base station may transmit only LP-WUS without activating LP-SS. In this case, the base station may have the LP-SS transmission function but have it disabled, or it may have been implemented or configured as a base station that can only transmit LP-WUS from the beginning.

[0228] Meanwhile, since LP-SS is an additional signal required to support the LP-WUS reception function, it is highly likely that the base station will not support the case where only LP-SS is transmitted. However, the process of activating LP-SS first (703) and transmitting (704) and then activating LP-WUS (703) and then transmitting (704) can be performed sequentially. After a series of processes, both LP-WUS and LP-SS are transmitted. In this case, it can be understood that there is a time difference between the time when LP-SS is activated and transmitted and the time when LP-WUS is activated and transmitted in order to provide the terminal with time to synchronize LP-WUR and measure the serving cell channel status through LP-WUR before receiving LP-WUS. In the following description, unless otherwise specified, it can be considered that the same process as activating both LP-WUS and LP-SS can be performed in this case.

[0229] Here are three examples of how to activate LP-WUS (and LP-SS). The methods described can be combined, and the activation methods are not limited to the examples described. Furthermore, the methods for activating LP-WUS and LP-SS can use the same or different methods. Furthermore, as previously described, whether LP-WUS and LP-SS are activated and the timing of activation can be the same or different. For convenience, the following description will represent LP-WUS in the description of the methods for activating LP-WUS and LP-SS. These methods can also be applied to LP-SS.

[0230] The first method is to directly link whether the LP-WUS-related system information provided by the base station is set and whether the LP-WUS is activated. That is, when the LP-WUS-related system information is obtained from the base station, it means that the base station is transmitting the set LP-WUS. At this time, it is assumed that the information related to the LP-WUS setting is set through a specific SIB, and the SIB is referred to as SIB_LP-WUS in the following description. SIB_LP-WUS includes information related to the sequence for receiving LP-WUS, information about LP-WUS occasion (LO) related to the time and transmission cycle of LP-WUS transmission, information about frequency resources through which LP-WUS is transmitted, etc. The information transmitted through SIB_LP-WUS is not limited to this, and information about LP-SS can also be included and set in SIB_LP-WUS.

[0231] In step 703, the base station provides the terminal with SIB_LP-WUS, which was not provided before activation, to activate LP-WUS. For example, if the list of SI-SchedulingInfo of SIB1 does not include an SI message related to SIB_LP-WUS, it means that LP-WUS transmission is not activated. If it is included and the system information is updated, it can be considered that the base station has activated LP-WUS transmission and LP-WUS transmission has occurred. Meanwhile, LP-WUS configuration information can be provided through SIB1 or MIB without providing a separate SIB for LP-WUS. This reduces the time required to obtain configuration information for LP-WUS of the terminal, but since the number of information bits that can configure MIB and SIB1 is limited, it can be considered only when the number of information bits required to configure LP-WUS is small. In the following description, the first method among the activation methods for LP-WUS and LP-SS transmission is referred to as activation method A.

[0232] The second method is to directly specify whether LP-WUS and LP-SS are enabled or disabled in the LP-WUS-related system information provided by the base station. For example, a base station capable of supporting LP-WUS can indicate in SIB_LP-WUS whether the base station is currently transmitting LP-WUS with 1 bit, along with the information required to receive LP-WUS as described above. Meanwhile, information indicating whether LP-WUS is enabled or disabled by the base station can be included in SIB_LP-WUS, but can also be conveyed in distinct system information such as SIB1 or MIB. When SIB1 or MIB indicates whether LP-WUS transmission of the base station is enabled or disabled, the SIB_LP-WUS information required for the terminal to receive LP-WUS can always be provided to the terminal regardless of whether LP-WUS transmission is enabled or can be provided only when LP-WUS transmission is enabled, as described in Activation Method A. In the following description, the second method among the methods for activating LP-WUS and LP-SS transmission is referred to as Activation Method B.

[0233] The third method is to indirectly correlate other operations set in the base station with the activation of LP-WUS. For example, when the base station operates as DTX, which periodically disables transmission on a specific channel or all channels in order to operate in energy saving mode, the base station can activate LP-WUS transmission when the base station is ON, and deactivate LP-WUS transmission when the base station is OFF. In this case, the correlation between the activation of DTX and LP-WUS of the base station can be provided through SIB_LP-WUS or together with the DTX-related settings. In addition, the third method among the activation methods of LP-WUS and LP-SS transmission is referred to as activation method C in the following description.

[0234] Meanwhile, activation method C may be applied dependently or independently of activation method A or B. For example, whether LP-WUS transmission is enabled may be determined through activation method C only when LP-WUS transmission is enabled through activation method A or B, or LP-WUS may be transmitted through the base station if LP-WUS transmission is enabled through activation method C even if activation is not enabled through activation method A or B.

[0235] Additionally, for RRC IDLE or INACTIVE terminals, whether LP-WUS is activated and the necessary information can be set through system information such as SIB_LP-WUS, while for terminals in RRC CONNECTED state, LP-WUS-related information and whether it is activated can be set through additional dedicated RRC signaling.

[0236] When the base station activates LP-WUS and LP-SS transmission (703) through the above-described method, the LP-WUS and LP-SS transmission continues through process 704. At this time, the LP-WUS and LP-SS transmission may be continuously performed, or the transmission of LP-WUS and LP-SS may be temporarily suspended and then transmitted repeatedly by another operation set in the base station after the LP-WUS and LP-SS are activated. For example, after the LP-WUS and LP-SS are activated through system information or RRC signaling, the LP-WUS and LP-SS transmission may be temporarily deactivated through MAC CE signaling, L1 signaling through DCI, or a related timer operation, and then signaling may be performed to activate the LP-WUS and LP-SS transmission again.

[0237] As another example, we can consider a case where the base station is in DTX operation. With LP-WUS and LP-SS transmissions enabled, LP-WUS may be transmitted only when the base station is ON, and may not be transmitted when the base station is OFF. The difference from the activation method C described above is whether the case where LP-WUS is not transmitted is considered as LP-WUS transmission being disabled. In this case, LP-WUS is only temporarily not transmitted when the base station is OFF, and the base station is not considered to have disabled LP-WUS transmission.

[0238] In step 704, the base station determines whether to disable the function while transmitting LP-WUS (and LP-SS) (705). If it determines that the function will continue to be transmitted LP-WUS and LP-SS without being disabled, the step 704 is continued. At this time, the base station can transmit both LP-WUS and LP-SS and then disable only LP-SS transmission as needed. This action can be performed in situations such as when the base station's operational resources are limited, as described above, or when it has been decided to no longer support LP-SS for terminals that absolutely need LP-SS.

[0239] If the base station decides to disable LP-WUS transmission in 705, the base station that was also transmitting LP-SS will no longer have a reason to transmit LP-SS and will therefore disable both LP-WUS and LP-SS transmissions. Disabling LP-SS when LP-WUS transmission is disabled can only be considered if LP-SS is used for LP-WUS reception. If LP-SS is used for synchronization purposes before receiving LP-WUS or to support the ability to replace serving cell measurements with LP-WUR to keep MR in OFF state for a long time when supporting LP-WUS reception operation of the UE, then there is no reason for the base station to transmit LP-SS when LP-WUS is no longer being transmitted. However, if LP-SS is used for other purposes, disabling LP-WUS transmission and transmitting only LP-SS can also be considered.

[0240] After the base station decides to disable LP-WUS and LP-SS transmission in step 705, it must notify the terminals connected to a specific cell and the terminals camping in the cell that the LP-WUS reception function is no longer supported through step 706, and it can be known that LP-WUS and LP-SS transmission is disabled through the examples of the method for providing activation information described in the activation step above.

[0241] The base station that has disabled LP-WUS and LP-SS transmission returns to state 701 and repeats the process described above. Although state 701, in which the base station does not transmit LP-WUS and LP-SS, is described as a default state in Fig. 7, if the base station is given a mandatory operation to transmit LP-WUS (and LP-SS), information for receiving LP-WUS (and LP-SS) is provided to the terminal as system information, and the terminal receives LP-WUS according to the information. At this time, a deactivation operation such as temporarily stopping LP-WUS and LP-SS transmission and an activation operation to resume transmission may be supported depending on specific conditions, and the process described in Fig. 7 may be considered for the corresponding operation.

[0242] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0243] Figure 8 is a drawing illustrating an example of operations and procedures required for a terminal capable of receiving LP-WUS to receive LP-WUS.

[0244] When the terminal is in the RRC CONNECTED state through the 800 process, it reports the capability to the network, and the information can be continuously stored in the network even if the RRC state of the terminal changes or the terminal moves to another base station. When reporting the capability, the terminal also reports the capability related to LP-WUS. At this time, it can report which type of WUR the terminal is implemented with. Specifically, it can report whether it can receive LP-WUS that can be received by WUR-A or LP-WUS that can be received by WUR-B. In addition, it can report LP-WUS-related capabilities including the time required to wake up the MR after receiving LP-WUS, whether LP-SS reception is possible, etc., but the reported information is not limited to this.

[0245] The terminal acquires system information about the base station during process 801. This system information includes not only information related to LP-WUS (e.g., SIB_LP-WUS) but also other system information. The terminal periodically receives system information and an instruction signal indicating whether the system is updated, and continuously determines whether the system information it has acquired is valid. At this time, SIB_LP-WUS-related information can be configured through the time point at which the updated system information begins to be transmitted and the configured SI-window information after receiving the instruction related to system information update.

[0246] The terminal determines whether the base station has activated the LP-WUS (and LP-SS) function through process 802. Whether the base station has activated the function or when it will be activated can be determined by obtaining system information through process 801. For example, based on the activation methods described above, according to activation method A, if LP-WUS-related information (e.g., SIB_LP-WUS) is received when obtaining the base station's system information, it can be considered that the base station has activated LP-WUS transmission. On the other hand, if the base station does not provide LP-WUS-related information, the terminal does not consider the base station to have activated the LP-WUS-related function. When activation method B is used, the terminal can determine whether the LP-WUS-related function is activated based on the value of the field indicating whether the LP-WUS-related function is activated among the acquired system information or the information provided through RRC signaling. When the LP-WUS-related function is activated through activation method C, it can be considered that the LP-WUS transmission operation is also activated in conjunction with other related functions. For example, if the base station's DTX operation is enabled, the base station's LP-WUS transmission can be determined to be enabled only when the base station is in the ON state.

[0247] If the terminal determines through process 802 that the base station has not activated LP-WUS and LP-SS transmission, the terminal repeats processes 801 and 802 to acquire system information of the base station and determine whether the LP-WUS function is activated. At this time, an RRC CONNECTED terminal can directly acquire system information like a terminal in an RRC IDLE or INACTIVE state, or if it cannot directly acquire the information, it can obtain the information through direct RRC signaling from the base station. If it is determined through process 802 that the base station has activated LP-WUS and LP-SS transmission, the terminal performs process 803 or 804.

[0248] The terminal can obtain all information necessary to receive LP-WUS (and LP-SS) while performing steps 801 and 802. Meanwhile, if the terminal obtains only information on whether LP-WUS and LP-SS are activated while performing steps 801 and 802, the terminal can perform a step (803) of obtaining specific information necessary to receive the corresponding signal only when the base station activates LP-WUS (and LP-SS) after obtaining the activation information. If the terminal can obtain all information necessary to receive LP-WUS and LP-SS in the previous step, as in the case of activation method A, step 803 can be omitted.

[0249] After the LP-WUS (and LP-SS) transmission of the base station is activated and the terminal acquires the information necessary to receive the corresponding signal, the terminal determines whether to activate the LP-WUS and LP-SS reception functions through process 804. At this time, activating the LP-WUS function by the terminal means that the existing operation performed by the terminal can be omitted due to LP-WUS reception. For example, the MR of the terminal must perform the operation of monitoring the PDCCH in the search space within the section set through DRX, etc., as illustrated in FIGS. 6a and 6b. However, only for terminals that have activated the LP-WUS function, whether a specific PDCCH should be received is determined through the LP-WUS received by the LP-WUR. At this time, the operation of receiving the PDCCH by the MR can be omitted until the instruction information indicating that a specific PDCCH should be received is received through the LP-WUS. That is, by operating only LP-WUR to receive LP-WUS and maintaining the MR in UDS state, unnecessary power consumption due to repetitive hardware ON / OFF switching and PDCCH monitoring can be reduced, thereby maximizing power saving of the terminal. At this time, the MR of the terminal can omit PDCCH-related monitoring indicated by LP-WUS, but if there are other essential operations such as RRM measurement or SDT (Small Data Transmission), it can periodically maintain the ON state for the corresponding operations. In addition, the state in which the MR is maintained is determined by the terminal implementation, but the time required to switch from OFF state to ON state (transition time) can be reported to the network during capability reporting in process 800.

[0250] Specifically, among RRC IDLE and INACTIVE terminals, LP-WUS can be received, and terminals with the corresponding function activated monitor LP-WUS in an LO periodically set through process 805, instead of receiving PEI or paging PDCCH for every i-DRX cycle as described in FIG. 6a. The LP-WUS received in the LO corresponding to the terminal indicates which terminal or which (sub)terminal group should occur through information bits mapped to the UE or UE (sub)group ID. The mapping relationship is provided to the terminal in advance, and in process 806, the terminal can determine whether paging PDCCH reception is indicated through the information transmitted through the LP-WUS. If the information bit mapped to the received LP-WUS does not correspond to the terminal, the operation of monitoring LP-WUS in the next LO is repeated. Meanwhile, if the information bit of the received LP-WUS corresponds to itself, that is, if an instruction to receive a paging PDCCH is issued from the PO, the UE receives the corresponding PDCCH in step 807. At this time, after receiving an instruction to receive a paging PDCCH through the LP-WUS, the paging PDCCH that the UE must receive is received from the PO set closest to the LO that received the LP-WUS, or when a specific offset value between the LO and the PO is given, such as when the base station sets the offset value between the LO and the PO as system information related to the LP-WUS, it can be received from the PO point in time that is closest to the point in time that can be monitored after the offset from the LO point in time. If the offset value is set as system information by the base station, all UEs monitoring the same LO have the same offset value.Meanwhile, in the case where multiple offsets are supported according to the terminal's capability reported in step 800, the location of the PO to be monitored may vary after receiving LP-WUS at a specific LO depending on the minimum transition time reported by the terminal's capability. For example, a terminal with a relatively short transition time may receive a paging PDCCH at a PO that appears immediately after the LO, whereas a terminal with a long transition time may not be able to receive the paging PDCCH at the MR at the PO that appears immediately after the LO and may receive the paging PDCCH at a PO located in the next cycle. In the above description, it is assumed that the PO is the same as the PO mentioned in the description of Fig. 6a. This means that the existing terminal and the terminal receiving LP-WUS share the same PO regardless of whether they support the LP-WUS reception function. It may also be considered to provide a separate PO for the terminal receiving LP-WUS.

[0251] Meanwhile, terminals in an RRC CONNECTED state can use LP-WUS for the purpose of triggering an operation to perform PDCCH monitoring in a specific section when LP-WUS is activated. For example, when the C-DRX operation is set to save power of a terminal in a CONNECTED state as described in FIG. 6b, whether the MR should switch from a sleep state to an ON state and perform PDCCH monitoring during the ON duration of the next C-DRX can be indicated through LP-WUS. Specifically, if an LP-WUS including information to wake up the terminal is transmitted in the LP-WUS monitoring occasion set for the CONNECTED terminal in step 805, the MR performs PDCCH monitoring for a specific section in step 807. At this time, the section in which the MR monitors the PDCCH may be the same as the section in which the terminal monitors the PDCCH in C-DRX when the LP-WUS function is not activated, or a separate monitoring section may be provided. At this time, a separate PDCCH monitoring interval is valid as a PDCCH monitoring interval of a specific terminal only when the LP-WUS function of the base station and the terminal is activated and PDCCH monitoring of the specific terminal is triggered.

[0252] After the MR of the terminal receives the PDCCH through process 807, it can receive the scheduled PDSCH according to the information of the PDCCH, or it can perform the necessary operation with only the information provided in the PDCCH. For example, if a system information update related instruction is given with a short message of paging PDCCH for RRC IDLE / INACTIVE terminals, the terminal that obtained the information can perform the operation of receiving the system information of the base station. In this way, after the terminal(s) instructed by LP-WUS have completed the essential operation, it can determine through process 808 whether to continue receiving LP-WUS (and LP-SS). If it is determined that the LP-WUS related function will continue, it returns to process 805 and repeats the operation of monitoring LP-WUS.

[0253] If the terminal decides not to activate the LP-WUS and LP-SS reception function in step 804 even though the base station transmits the LP-WUS or LP-SS, or if the terminal decides not to continue the LP-WUS function in step 808 after performing a PDCCH reception operation through LP-WUS in step 807, the terminal may perform the same operations as the existing terminal when the LP-WUS function is not supported (e.g., the operations of FIGS. 6A and 6B). At this time, whether to activate the operation of receiving LP-WUS and LP-SS may be determined by the terminal implementation, but whether a specific condition is satisfied may be related to whether the LP-WUS function is activated or continued. Specifically, the LP-WUS function can be activated or continued only when a specific condition is satisfied in step 804 or step 808. At this time, the condition that the terminal must satisfy before performing the LP-WUS function is named an entry condition, and the specific entry condition is described in detail in Embodiment 2. Additionally, if the terminal does not satisfy the entry condition, it may perform the same operation as the existing terminal, or it may perform an operation that periodically checks for the entry condition while performing the operation of the existing terminal. A detailed description of the operation is provided in Example 2 with reference to FIG. 9.

[0254] Meanwhile, even if a terminal satisfies the entry conditions and activates LP-WUS, a situation may arise where the LP-WUS reception function deteriorates due to movement of the terminal or channel change. Therefore, while activating the LP-WUS function and monitoring LP-WUS, conditions may be needed to determine whether the LP-WUS reception result is reliable. In the present disclosure, the condition for determining whether the LP-WUS reception capability is reliable while the terminal activates the LP-WUS function is named an exit condition, and a specific description of the corresponding operation is described in Example 3.

[0255] Meanwhile, an RRC CONNECTED terminal may utilize the LP-WUS function used for an RRC IDLE or INACTIVE terminal. Specifically, if a search space capable of receiving information such as paging PDCCH is included in the active BWP of an RRC CONNECTED terminal, the terminal may obtain information in the same manner as an IDLE or INACTIVE terminal obtains paging information and system information. In this case, the terminal may also consider monitoring the LP-WUS monitored by the RRC IDLE or INACTIVE terminal to obtain paging information or necessary system information in the same manner as obtaining necessary information by utilizing the LP-WUS function in the RRC IDLE or INACTIVE state.

[0256] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps. Furthermore, the specific terminology used in the above examples may be modified, and the scope of the present disclosure is not limited to the examples described herein.

[0257] <Example 2>

[0258] The second embodiment of the present disclosure describes conditions that a terminal must satisfy before activating the LP-WUS function. Specifically, the description describes entry conditions that a terminal must satisfy before performing an operation to receive LP-WUS, replacing a conventional operation, and the actions that the terminal performs based on whether or not the conditions are satisfied.

[0259] Before explaining the specific conditions, let me explain why the entry condition is necessary. When the LP-WUS function is activated, the power consumed to receive LP-SS and LP-WUS is relatively less than the power consumed by the MR to receive the PDCCH, but the ability to detect LP-WUS, i.e. the coverage of LP-WUS, is likely to be smaller than that of other existing signals (e.g., paging PDCCH). In this case, if the terminal switches to UDS state to save power and receives LP-WUS through LP-WUR even though the channel environment is poor for receiving WUS, there is a high probability that the LP-WUS transmitted by the base station will not be properly received. If the terminal does not receive the LP-WUS and continues to maintain the UDS state even though the base station transmits LP-WUS to wake up a specific terminal, the base station will determine that the terminal has suddenly turned off, which will affect not only the performance of the terminal but also the system performance of the base station. Therefore, the minimum conditions that can be used to check whether the terminal can successfully receive LP-WUS before switching to UDS state and receiving LP-WUS instead of the previously received PDCCH, i.e., the minimum conditions that must be satisfied before activating LP-WUS, can be given as entry conditions for LP-WUS monitoring.

[0260] First, before the terminal determines whether the entry condition is satisfied, the base station must activate LP-WUS transmission as described in 802 to 803 of FIG. 8, and the terminal must obtain LP-WUS-related information. At this time, the provided LP-WUS-related information may include settings related to the entry condition. In addition, specific entry conditions or the presence or absence of entry conditions may vary depending on the RRC state of the terminal. That is, the entry conditions that an RRC IDLE or INACTIVE terminal must determine may be different from the entry conditions that an RRC CONNECTED terminal must determine. In some cases, in a specific RRC state, regardless of whether the entry condition is satisfied, if the base station activates the LP-WUS transmission function, the terminal may be configured to unconditionally activate the LP-WUS reception function. For example, if an RRC CONNECTED terminal receives LP-WUS-related settings through RRC signaling, etc., it considers that the LP-WUS transmission function of the base station has been activated, and can perform LP-WUS monitoring operation after a specific time from the activation time.

[0261] Referring to Fig. 8, the time when the terminal determines the entry condition can be largely divided into two processes: process 804 and process 808. The terminal in process 804 can be considered to determine the entry condition immediately after the base station activates the LP-WUS function but before the terminal activates the LP-WUS function, or before the terminal activates the LP-WUS function for the first time after camping at the base station where the LP-WUS function is activated in an IDLE or INACTIVE state, or before the terminal activates the LP-WUS function after establishing an RRC connection with the base station. At this time, as explained above, the method for activating LP-WUS may vary depending on the RRC state of the terminal, and whether or not the entry condition is determined and the specific conditions may also vary depending on the RRC state or the purpose of which PDCCH reception LP-WUS is used to trigger. For example, an RRC IDLE or INACTIVE terminal acquires the system information of the base station, determines whether the base station transmits LP-WUS based on LP-WUS-related information, and determines the entry conditions for activating the LP-WUS reception function on its own, whereas an RRC CONNECTED terminal can activate the LP-WUS function through RRC signaling in addition to updating system information. Specifically, a terminal in an RRC CONNECTED state can have the base station communicate unicast with the terminal and receive reports on the terminal's status, such as the terminal's channel, LP-WUS reception capability, or LP-WUR reception status. Therefore, the base station can request related information from the terminal and determine whether to transmit LP-WUS to the terminal based on the acquired information. In this case, if information related to LP-WUS is provided and an activation instruction is given through RRC signaling, it can be considered that the terminal activates and monitors the LP-WUS function from a set point in time without having to determine the entry conditions.Alternatively, DCI or MAC CE-based signaling can be introduced additionally.

[0262] Specifically, the LP-WUS function of the base station can be activated through RRC signaling, and the time and whether the terminal actually activates LP-WUS monitoring and whether it is activated can be notified through DCI signaling or MAC CE signaling. This is because, if the base station determines that it temporarily does not have enough resources to support LP-WUS or that the channel status of the terminal makes it difficult to successfully receive LP-WUS, it is necessary to instruct the terminal to disable the operation of receiving LP-WUS for a certain period of time through DCI signaling or MAC CE signaling. In this case, the terminal can start LP-WUS monitoring when it additionally receives DCI or MAC CE signaling after receiving RRC signaling, or perform LP-WUS monitoring from a specific point in time after receiving LP-WUS activation-related information through RRC signaling, but when it receives DCI or MAC CE signaling for LP-WUS function deactivation, it can disable the LP-WUS monitoring operation until it receives the next DCI or MAC CE signaling related to LP-WUS function activation or until the time of a specific timer expires. At this time, the timer is used to count the LP-WUS function deactivation interval. Alternatively, it can be used to count the LP-WUS reception function activation interval after LP-WUS function activation is indicated by DCI or MAC CE signaling.

[0263] As previously explained, while the base station can activate the LP-WUS function of a connected state terminal through additional DCI or MAC CE signaling alone or a combination of additional signaling and a timer after RRC signaling to the terminal, the timer alone can also activate the LP-WUS function. For example, a terminal that has received an instruction to activate LP-WUS through RRC signaling performs LP-WUS monitoring operation from a time specified by the base station or the standard, and simultaneously starts counting a specific timer. When the time of the timer expires, the LP-WUS monitoring operation is deactivated unless separate information (e.g., time extension of the timer) is received from the base station, and the existing PDCCH monitoring operation is performed as illustrated in FIG. 6b. Among the cases described above, when the base station activates the LP-WUS function for terminals in RRC CONNECTED state through RRC signaling, terminals that perform LP-WUS monitoring immediately from a time specified by the base station or the standard do not require a separate entry condition, and only the activation of the LP-WUS function by the base station can be regarded as an entry condition. On the other hand, if the terminal is given the task of performing LP-WUS monitoring only after receiving a separate DCI or MAC CE signaling after the RRC signaling, receiving the DCI or MAC CE signaling can be regarded as an entry condition for the terminal to start LP-WUS monitoring.

[0264] In the case of a terminal in the 808 process, the LP-WUS function is already activated, and the LP-WUS instructs the MR to receive PDCCH, performs operations such as receiving PDCCH and related PDSCH, and then the entry condition can be determined to select whether to operate in the LP-WUS receiving mode again or return to the operation of the terminal before activating the LP-WUS.

[0265] Specifically, when a terminal that has activated the LP-WUS function receives an LP-WUS indicating PDCCH reception as illustrated in FIG. 8, the terminal may not perform the operation of monitoring LP-WUS through LP-WUR while operating the MR to receive a PDCCH at a given PDCCH monitoring occasion (807). That is, the terminal does not expect to receive another PDCCH reception instruction through LP-WUS while receiving the PDCCH instructed by the LP-WUS to receive the PDCCH. In addition, the period during which the terminal stops the LP-WUS monitoring operation may continue until the terminal performs a necessary operation after receiving the PDCCH. In this case, the time it takes for the terminal to perform the necessary operation may vary depending on what information was received through the PDCCH and PDSCH. In this case, the fact that the terminal wakes up by LP-WUS and receives PDCCH may be regarded as the deactivation of the terminal's LP-WUS function, and the entry condition may need to be determined in order to monitor LP-WUS again. Alternatively, there may be cases where the entry condition is determined and cases where it is not determined. For example, there may be cases where the entry condition is determined only when the time for which LP-WUS monitoring is stopped is longer than a specific time after the terminal's MR is operated due to an instruction from LP-WUS. However, this case may be considered when the LP-WUS function is stopped while the terminal operates the MR after receiving the LP-WUS instructing the terminal to receive PDCCH. If a terminal that has activated the LP-WUS reception function is required to unconditionally monitor LP-WUS on a given LO regardless of whether the LP-WUS instructed the terminal to receive PDCCH, step 808 of FIG. 8 may be omitted. If the 808 process is omitted, the terminal repeats the 805 process unless there is a problem with the LP-WUS reception function.A method for determining whether there is a problem with the LP-WUS reception function is specifically described in Embodiment 3. Alternatively, a certain period of time or a certain cycle during which LO is not to be monitored after LP-WUS triggers PDCCH reception of the terminal may be specified in a standard manner or may be provided as LP-WUS-related information such as system information. That is, after the terminal receives LP-WUS that triggers PDCCH reception, the LP-WUR of the terminal does not monitor LP-WUS on LO for a certain cycle and repeats the LP-WUS monitoring operation (805) after the specified period of time has elapsed. At this time, as in the example described above, the terminal may deactivate the LP-WUS function if there is a problem with the LP-WUS reception function.

[0266] Specifically, when an RRC IDLE or INACTIVE terminal operates MR by instructing LP-WUS to receive PDCCH in process 806, examples of subsequent operations of the terminal according to the received information are described.

[0267] The first example is when a paging message scheduled for the paging PDCCH is received, but there is no corresponding paging message for the UE. In this case, two main possibilities can be considered. The first is when the paging message is intended for another UE belonging to the same UE subgroup as the UE. In this case, it is assumed that the LP-WUS instructs reception of the PDCCH for a specific subgroup or specific subgroups. In other words, UEs belonging to the same subgroup receive the same LP-WUS, and the determination of whether to monitor the PDCCH based on the information in the received LP-WUS is also the same. Therefore, this means that although the UE successfully receives the LP-WUS, no subsequent action is required after receiving the paging PDCCH, so it returns to step 805 to resume LP-WUS monitoring and switch the MR to the OFF state. The second case is when the UE determines in step 806 that the LP-WUS instructed PDCCH reception, but the LP-WUS did not actually instruct PDCCH reception. That is, when LP-WUS information is received differently from what was actually transmitted (decoding failure) or when the terminal believes it has received LP-WUS when no LP-WUS was sent (false alarm). If the terminal monitors PO but does not receive paging PDCCH, it can be determined that LP-WUS decoding failure or false alarm has occurred.However, if a paging PDCCH is transmitted for a different subgroup, the terminal can determine whether the information it received is incorrect by checking whether the IDs appearing in the paging messages of the terminals that actually received the paging message are included in the set of IDs of the terminals that were expected to receive the paging message based on the LP-WUS information received by the terminal, thereby determining whether a decoding failure or false alarm occurred.

[0268] If the terminal can determine whether LP-WUS decoding failure or false alarm has occurred, it can be considered that when MR is switched to ON due to LP-WUS decoding failure or false alarm and PDCCH is received, LP-WUS monitoring can be resumed and LP-WUS function can be continued only if the entry conditions are met. On the other hand, if there is no LP-WUS decoding failure or false alarm but there is no paging message for the terminal, LP-WUS monitoring can be resumed immediately without a separate entry condition determination, or whether LP-WUS monitoring operation can be resumed based on a timer. For example, if a specific timer is started from the time LP-WUS instructing PDCCH reception is received and the timer has not expired when trying to resume LP-WUS monitoring, the LP-WUS function can be used without determining the entry conditions again. However, if the timer has expired, it means that that much time has passed, so the entry conditions can be determined again and the LP-WUS function can be continued if the conditions are met. In this specification, a timer that operates when the activated LP-WUS function operation is stopped due to PDCCH reception by LP-WUS is collectively referred to as timer A. At this time, timer A is initialized at the time when the LP-WUS function of the terminal is activated, and counts when PDCCH reception is indicated by LP-WUS.

[0269] Meanwhile, there may be cases where it is difficult for the UE to determine whether the LP-WUS decoding failure or false alarm occurs, such as when the LP-WUS instructs PDCCH reception of multiple subgroups. In such cases, only when a false alarm is confirmed (for example, when no paging PDCCH is received from the PO), the entry condition is determined when resuming the LP-WUS reception operation. In other cases, the UE may determine whether to determine the entry condition for resuming the LP-WUS reception operation based on timer A in the same way as the example described above, or may resume LP-WUS monitoring immediately without a separate entry condition determination.

[0270] The second example is when the terminal receives a paging PDCCH instructed by LP-WUS and the PDCCH transmits a short message. After receiving the short message and completing the reception of system information, the terminal can determine whether to resume the LP-WUS monitoring operation that was stopped in step 808. At this time, the entry condition can be determined to unconditionally activate the LP-WUS monitoring operation, or the entry condition determination can be omitted for that case. Alternatively, as in the first example, timer A can be operated and whether or not to determine the entry condition before resuming the LP-WUS monitoring operation can be determined based on whether timer A has expired.

[0271] The third example is when the paging message obtained through the PDSCH scheduled as the paging PDCCH contains information commanding the RRC CONNECTION of the corresponding terminal. In this case, the terminal must perform an operation such as switching to the RRC CONNECTED state and receiving the data to be received. In other words, the RRC state of the terminal changes. In this case of the RRC state change, it is assumed that all LP-WUS-related operations or related timers that were operating in the RRC IDLE or INACTIVE state have been reset. Therefore, when the RRC CONNECTED state is switched back to the RRC INACTIVE or RRC IDLE state, the initial operation can be repeated to activate the LP-WUS reception function. That is, assuming that steps 800 and 801 of FIG. 8 have already been performed in the RRC CONNECTED state, steps 802 can be performed. Alternatively, the base station may determine that the LP-WUS function has been activated and perform steps 804. As in the first and second examples, operations based on timer A may also be performed. However, since this method, unlike the previous examples, involves a transition of the RRC state, there is a high possibility that timer A will expire when it operates based on timer A.

[0272] Alternatively, the base station can provide LP-WUS-related information when or before instructing the RRC INACTIVE or RRC IDLE state transition in the RRC CONNECTED state. That is, the base station can provide information such as whether the LP-WUS transmission function for terminals in RRC IDLE and INACTIVE states is activated, and if updated information is available, it can provide the information to terminals with LP-WUS reception capability. If the terminal has received LP-WUS-related information from the base station before transitioning the RRC state in this way, the terminal can determine the entry conditions before transitioning the RRC state, and if the state is capable of LP-WUS activation (if the entry conditions are satisfied), the LP-WUS reception function can be activated immediately after transitioning to the RRC IDLE or INACTIVE state. Alternatively, the terminal can recognize only that the base station has activated LP-WUS transmission, and activate the LP-WUS function as long as the entry conditions are satisfied, regardless of the RRC state transition timing. Alternatively, since the terminal in the RRC CONNECTED state performs actions such as reporting channel measurement results to the base station, the base station can determine whether the terminal is in a state where the LP-WUS function can be activated. Accordingly, it is also possible to consider a case where the terminal receives an instruction from the base station that it can activate the LP-WUS function immediately without determining its own entry conditions after transitioning to the RRC IDLE and INACTIVE states.The methods explained through the third example above are about how to determine the entry conditions of the terminal and how to activate LP-WUS when the terminal in the RRC IDLE or INACTIVE state performs PDCCH monitoring due to LP-WUS and then performs RRC CONNECTION. However, in a broader sense, it can be seen as an explanation of the operation when the terminal that was in the RRC CONNECTED state and then transitions to the RRC IDLE and INACTIVE states activates the LP-WUS function.

[0273] To summarize the terminal procedures for the 808 process for the first, second, and third examples above, when the LP-WUS monitoring operation of the terminal has stopped for a longer period of time than the time given based on timer A, or when there is a transition of the RRC state of the terminal, or when it is determined or suspected that the MR has performed the PDCCH monitoring operation due to the LP-WUS decoding failure or false alarm of the terminal, the 808 process can determine the entry conditions for determining whether the LP-WUS monitoring operation can continue, and in other cases, the LP-WUS monitoring operation can be resumed without performing a separate entry condition determination process. Among the operation examples of the terminals described above, only some of them may be applied to specific conditions, or multiple operations may be combined.

[0274] Meanwhile, in the case of an RRC CONNECTED terminal, a process may be required to determine whether LP-WUS monitoring can continue in step 808, just like in the case of a terminal in an RRC IDLE or INACTIVE state. As described above, step 808 is required when LP-WUS monitoring is not performed while the MR performs a specific operation, such as receiving a PDCCH when PDCCH monitoring is triggered by LP-WUS. If the terminal is required to continue LP-WUS monitoring in the next LO or after a certain period regardless of whether PDCCH monitoring is triggered by LP-WUS, step 808 may be omitted, and step 805 is repeated unless the conditions described in Embodiment 3 are satisfied or the base station deactivates the LP-WUS function. This means that even if PDCCH reception is triggered by LP-WUS and the MR performs a specific operation, if LP-WUS is received again in the next LO or after a certain period, the terminal performs the PDCCH monitoring operation related to the LO.

[0275] Whether a terminal is required to continue LP-WUS operation from a specific point in time after PDCCH monitoring is triggered due to LP-WUS or whether continuity should be determined based on the status of the terminal may be directly or indirectly specified in the specification, or the base station may set it for the terminal(s). In this case, the difference between the LP-WUS monitoring operation of terminals in RRC IDLE and INACTIVE states and the other states is that since RRC IDLE and INACTIVE terminals are not directly communicating with the base station, it is difficult for the base station to determine whether the LP-WUS function of the terminal is activated and whether LP-WUS monitoring is in operation. On the other hand, in the case of RRC CONNECTED terminals, the base station must know the specific operations of the terminals, such as which terminal has activated LP-WUS monitoring (operation 805 in FIG. 8), whether LP-WUS monitoring is in operation at a specific point in time, and whether PDCCH monitoring is in operation instead of LP-WUS monitoring. In other words, the difference is that, compared to a terminal in RRC IDLE or INACTIVE states where there are actions that can be selected by the terminal implementation, a terminal in RRC CONNECTED state must operate as set by the base station or as specified in the standard. Therefore, if there is a change in the operation of an RRC CONNECTED terminal, such as stopping while monitoring LP-WUS, the time of the change must be provided by the base station or specified in the standard so that the terminal and the base station have the same understanding of the terminal's operation.

[0276] If a terminal in a CONNECTED state receives an LP-WUS that triggers PDCCH reception, and then does not perform LP-WUS monitoring, and then resumes LP-WUS monitoring after completing the necessary operations of the MR, and determines whether to continue the LP-WUS reception function in process 808, the following operations can be considered as candidates.

[0277] - Action 1: Regardless of the operation of the MR, the LP-WUS reception function is considered disabled from the LO onwards. Until the base station re-enables the LP-WUS function through RRC, MAC CE, DCI signaling, etc., the existing operation (Figure 6b) is performed without LP-WUS monitoring being activated.

[0278] - Action 2: Disable LP-WUS reception function when a specific time or a specific LO monitoring cycle (or a specific PDCCH monitoring, or C-DRX cycle) has passed based on the timer. The timer counts down when PDCCH reception with LP-WUS is triggered, and if the timer has not expired between the time when the terminal resumes LP-WUS monitoring, LP-WUS monitoring continues. If the timer has expired, the LP-WUS reception function is considered disabled. The time when LP-WUS monitoring is to be resumed can be determined based on the time of the last signal received or transmitted by the terminal, or can be determined based on the time when the base station transmits information to the terminal notifying that there is no more data to be transmitted or received. Alternatively, it can be determined based on the expiration of drx-InactivityTimer or a timer with a similar function during the C-DRX operation of the terminal. When the LP-WUS receiving function is disabled due to the expiration of the timer, the existing operation (Fig. 6b) is performed without activating LP-WUS monitoring until the base station re-activates the LP-WUS function through RRC, MAC CE, DCI signaling, etc.

[0279] - Operation 3: A method in which the terminal receives information from the base station regarding whether to perform LP-WUS monitoring for the terminal in the future, since the base station knows the current status of the terminal, such as the channel status of the terminal. For example, if the base station provides information on when to resume LP-WUS monitoring, LP-WUS monitoring is resumed according to the information. If information on when to resume LP-WUS monitoring is not provided, the LP-WUS function is considered to be disabled. Until the base station re-enables the LP-WUS function through RRC, MAC CE, DCI signaling, etc., the existing operation (Fig. 6b) is performed without activating LP-WUS monitoring.

[0280] The above-described actions 1 to 3 illustrate some of the terminal's operational examples, and each action can be supported independently or combined. Furthermore, the specifications may specify which actions can be performed depending on the situation or condition, or the base station may directly or indirectly provide information on which actions to perform. For example, actions for a connected terminal may be considered, such as performing action 1 when no information is received from the base station, or performing action 2 or action 3 when timer information or information regarding the resumption of LP-WUS monitoring is provided by the base station.

[0281] In summary, when determining the entry conditions for LP-WUS monitoring in steps 804 and 808, the same entry conditions may be considered. However, the determination when a terminal first activates LP-WUS after the base station has activated LP-WUS or when the terminal first camps on the base station is different from the situation where the terminal has already activated the LP-WUS function, so a distinct entry condition may be considered. The determination of entry conditions using the timer described above can be seen as an example of considering different entry conditions. In step 804, the entry condition must be unconditionally satisfied before activating the LP-WUS function, but in step 808, the entry condition does not need to be evaluated until the timer expires, and the entry condition must be reevaluated when the timer expires. Therefore, it can be seen that different entry conditions are considered in this part. This is just an example, and the application of different entry conditions in steps 804 and 808 is not limited to this.

[0282] Meanwhile, in the case where the LP-WUS function is determined to be re-activated in the 808 process, the terminal during the period of determining the entry condition must perform the operation of the existing terminal, as shown in Fig. 6a or Fig. 6b, before the LP-WUS function is re-activated.

[0283] So far, we've explained when a terminal determines the entry conditions for activating the LP-WUS function. Now, we'll explain what the entry conditions are. Typically, terminals must perform channel measurements using signals commonly used as RSs (Reference Signals) to determine whether they can receive stable service from the serving cell. Terminals in RRC CONNECTED state report measured channel values ​​according to the base station's instructions. Terminals in RRC IDLE or INACTIVE state do not report channel measurement values ​​to the base station, but require an action to measure SSS transmitted within SSB at specific intervals to determine whether it meets a given criterion. Specifically, the terminal autonomously determines whether a specific criterion is met using the measured channel values ​​based on formulas specified in the standard and values ​​set as system information by the base station. For example, an RRC IDLE or INACTIVE terminal determines whether it meets criterion S, which serves as the basis for performing cell reselection, based on the SSS values ​​received from the serving cell over a certain period and the values ​​provided by the base station. At this time, criterion S can be said to be satisfied if the Srxlev and Squal values ​​have values ​​greater than 0, and the Srxlev and Squal values ​​can be derived based on the RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) values ​​of the channel measured by the terminal and the values ​​provided by the base station or specified in the standard.If criterion S is met, the terminal continues to camp on the cell and receives paging information, etc., and if criterion S is not met continuously for a specific number of i-DRX cycles (e.g., 4 i-DRX cycles), the terminal measures the channel of the neighboring cell provided to the serving cell to find a new cell suitable for camping. Therefore, the terminal measures the channel of the serving cell to periodically determine whether the serving cell is suitable regardless of the RRC state, and the periodic channel measurement and the corresponding value can be used to determine the entry condition before activating LP-WUS reception. This is because the channel condition experienced by the terminal is closely related to determining whether LP-WUS can be successfully received. However, the specific contents and criteria of the entry condition for determining the activation of the LP-WUS function may be the same as or different from the conditions and criteria (criterion S) in the serving cell measurement described above.

[0284] If the criterion S used in the cell reselection process and the criteria and value derivation process for determining the entry condition are completely identical, this means that a UE in RRC IDLE or INACTIVE state maintaining a camping state in a cell satisfies the entry condition required to activate the LP-WUS function, and it can be supported when the coverage of MR and the coverage of LP-WUR are guaranteed to be similar. However, since LP-WUR consumes less power than MR, the coverage of LP-WUR is expected to differ from that of MR, and accordingly, it is highly likely that the criterion used as the entry condition and the cell reselection criterion (criterion S) will be different. Specifically, an RRC IDLE or INACTIVE UE is likely to be required to satisfy an entry condition that can be satisfied when the channel condition is better than the channel condition satisfying criterion S in order to use the LP-WUS function in the cell where it camped. In the following description, the standard for evaluating the entry condition based on the channel measurement result of the UE is named criterion A. The entry condition for activating LP-WUS monitoring of a terminal with LP-WUS function may be determined solely by whether criterion A is satisfied, or the entry condition may be considered satisfied when criterion A or / and other separate conditions are satisfied.

[0285] As previously explained, in the case of a terminal in RRC IDLE or INACTIVE state, since it is not directly connected to the base station and cannot exchange information, the terminal can directly determine criterion A based on the formula specified in the standard and the channel measurement value performed by the terminal. At this time, the method for a terminal supporting the LP-WUS function to measure a channel can be largely divided into two methods. The first method is a method in which the MR measures the channel based on the channel(s) commonly used for channel measurement, such as SSS, just like a general terminal, and the second method is a method in which the LP-WUR that directly receives the LP-WUS measures the channel. The LP-WUR possessed by the terminal may not support the channel measurement function depending on the implementation, but the LP-WUR covered in this disclosure is assumed and described as supporting the channel measurement function.

[0286] At this time, a terminal with the LP-WUS function must measure the channel status in order to determine criterion A as an entry condition, and through this, it can determine whether the channel is suitable for activating the LP-WUS function. Specifically, if the channel measured by LP-WUR is higher than a specific threshold, the channel status can be determined to be good, and if it is equal to or lower than the specific threshold, the channel status can be determined to be bad. At this time, the method for providing the threshold of criterion A can be largely divided into two. In the following description, it is assumed that when the receiver measures the channel, it basically measures the RSRP value, which measures the received power of the signal, and the RSRQ value, which measures the quality of the signal. However, this is not limited to this and other channel measurement values ​​can also be utilized.

[0287] - Method 1: When the base station provides the minimum channel measurement value that must be satisfied as a threshold, the condition is considered satisfied only if the RSRP and RSRQ values ​​measured by the terminal are greater than the corresponding channel measurement value. In other words, assuming that the base station provides threshold_RSRP and threshold_RSRQ values, the terminal can be considered to have satisfied criterion A when RSRP > threshold_RSRP and RSRQ > threshold_RSRQ. At this time, the threshold_RSRP and threshold_RSRP values ​​can be set by the base station or specified in the specification. However, since there is a limit to all cells applying the values ​​specified in the specification, the threshold value can be adjusted to suit the circumstances of the base station by applying the offset provided by the base station from the reference value specified in the specification. In addition, since the receiver that measures the channel may vary, the base station may provide an offset value that can adjust the threshold depending on which receiver is used, or a rule may be specified to adjust the offset value depending on the MR or LP-WUR implementation method of the terminal. For example, if LP-WUR with a large noise figure value is implemented, a larger offset may be required to be applied.

[0288] - Method 2: The threshold value provided by the base station or specified in the standard is constant, and when calculating the RSRP and RSRQ values, in addition to the measured channel value, the offset value provided by the base station and the LP-WUR characteristic values ​​of the terminal are applied to define variables whose values ​​can change depending on the characteristics of the base station and the terminal, thereby configuring criterion A. For example, after defining variables called Srsrp_wus-entry and Srsrq_WUS-entry, criterion A can be set to satisfy Srsrp_wus-entry > threshold and Srsrq_WUS-entry > threshold_RSRQ. At this time, the threshold may be the same value used in the two formulas, or different values ​​may be set, and may be provided by the base station or may be specified as a specific value (for example, 0) in the standard like criterion S. Additionally, the values ​​of Srsrp_wus-entry and Srsrq_wus-entry can be derived by subtracting the offset values ​​provided by the base station from the RSRP and RSRQ values ​​measured by the terminal according to a formula.

[0289] The method by which the base station sets the threshold to the terminal has been described above, but methods 1 and 2 can be combined to configure threshold and criterion A. This only differs depending on how the formulas for criterion A are constructed, but the approach of determining whether the terminal satisfies the minimum channel measurement value that must be satisfied can be seen as the same. The values ​​provided by the base station in these methods can be provided to terminals with the LP-WUS function within the cell by considering the status of the base station, such as the cell operation status, through the base station implementation. However, it can be additionally considered that the receiver measuring the channel and the receiver receiving the LP-WUS may be different, and that the receiver receiving the LP-WUS may have a different type depending on the implementation of the terminal.

[0290] First, we describe the case where the terminal uses only MR to determine criterion A. In this case, the terminal can measure the channel by utilizing channels previously transmitted by the base station, such as SSB. While channel measurement can be based on the SSS signal, which is typically used for SSB channel measurement, the PSS, which is used as another synchronization signal, can also be utilized, and the channel can also be measured by including PBCH-DMRS, etc. Based on the methods described above, we describe the case where criterion A is configured as a channel value measured by MR.

[0291] - When configuring criterion A using only MR measurement values ​​using Method 1: All terminals in the cell measure RSRP and RSRQ using MR, but the coverage range for smoothly using the LP-WUS function may differ depending on which LP-WUR type the terminal has implemented. Therefore, multiple threshold values ​​that can be applied differently may be provided depending on the LP-WUR type. Alternatively, after receiving a common threshold value from the base station, a rule that can compensate according to the LP-WUR type may be applied. If the coverage is relatively wide (WUR-B), the threshold may be adjusted with a small offset value, and if the coverage is narrow (WUR-A), the threshold may be adjusted with a large offset value. Alternatively, a threshold may be assigned according to a specific type of LP-WUR, and for LP-WURs with wider or narrower coverage than the corresponding type, a rule may be specified or left to the terminal implementation so that the terminal can adjust the threshold. That is, different thresholds can be applied depending on the type of LP-WUR. In the case of a terminal that implements multiple LP-WUR type functions, when multiple thresholds are given, the type of LP-WUR that can receive LP-WUS is determined based on which threshold the channel measurement value of the MR exceeds. If the threshold of WUR-A is not satisfied but the threshold of WUR-B is satisfied, it means that LP-WUS can be received only with the LP-WUR implemented with WUR-B. If both types satisfy the threshold, it is up to the terminal implementation to decide which WUR to use to receive LP-WUS.

[0292] - When configuring criterion A using only MR measurement values ​​using Method 2: It can be seen that criterion S used for cell reselection described above is the same as the case where the threshold is specified as 0 in the specification in Method 2. In addition, since criterion S is also performed by the MR of the terminal before activating the LP-WUS function, criterion A can be simply configured by considering a specific offset value in criterion S. For example, as described above, in calculating Srxlev and Squal in criterion S, in addition to the RSRP and RSRQ values ​​measured by the MR, the base station provides the offset values ​​required as system information. At this time, the base station can provide other offset values ​​required in the process of calculating criterion A or values ​​required for additional correction. This is because, as described above, the coverage of LP-WUR is smaller than that of MR, so it is necessary to configure criterion A to satisfy the entry conditions under better channel conditions. If you want to use the same formula used in criterion S, you can configure criterion A to be provided with offset values ​​called Qrsrp-wusentry (dB) and Qrsrq-wusentry (dB) so that the terminal subtracts the offset values ​​from the values ​​derived from the existing formulas when calculating Srxlev and Squal.

[0293] In another case, criterion A can be considered based solely on the measured values ​​of LP-WUR. LP-WUR requires a signal to measure the channel. While WUR-B can receive signals such as SSB that the base station previously transmits, WUR-A cannot receive conventional signals such as SSB and can only receive envelope detection-based OOK signals. Therefore, channel measurement can be performed based on signals such as LP-SS. This means that WUR-A terminals cannot determine the entry conditions to activate the LP-WUS function for base stations that do not transmit or activate LP-SS. Alternatively, in this case, WUR-A terminals can determine whether criterion A is met solely based on the measured values ​​of MR, rather than the measured values ​​of LP-WUR. Based on the methods described above, we will explain the case where criterion A is configured based on the channel values ​​measured by LP-WUR.

[0294] - When configuring criterion A only with LP-WUR measurement values ​​using Method 1: When measuring only with MR, it can be assumed that the channel measurement capabilities of the MRs of the terminals in the cell are similar, so it was considered that the difference between the channel measurement value of the MR and the LP-WUS reception function of the LP-WUR may vary depending on the type of LP-WUR implemented in the terminal. However, when the LP-WUR of the terminal measures the channel, the same threshold value can be set. This is because the difference in reception function can be judged by whether the threshold value is satisfied, etc. However, since the channel can be measured based on a different signal depending on the LP-WUR implementation of the terminal, a different threshold value can be set taking this into consideration. Specifically, a terminal implemented with WUR-A can measure a channel based on LP-SS, and a terminal implemented with WUR-B can measure a channel based on LP-SS. Since they utilize the same signals (typically, SSS) that MR uses to measure the channel, it is possible to distinguish and set which threshold to use when measuring the channel using which signal. Accordingly, the terminal can apply different thresholds depending on which signal is used to measure the channel. As in the case of measuring the channel only with MR, the threshold can be provided in addition to being set directly, by specifying a reference value and providing only an offset value, or by providing the threshold difference according to the signal as an offset value.

[0295] - When configuring criterion A using only LP-WUR measurement values ​​using Method 2: Just like when measuring channels only with MR, it can be configured simply by applying only the offset value in criterion S. If the base station provides the UE with the minimum channel value that must be satisfied for cell reselection as well as the minimum channel value that must be satisfied to activate the LP-WUS function as an offset, the UE can subtract the corresponding offset from the value measured by LP-WUR to determine whether the condition is satisfied. However, as explained in Method 1 of measuring only with LP-WUR, the signal used by LP-WUR for channel measurement may vary depending on the LP-WUR type, so the channel value provided as an offset may also be set differently depending on which signal was used. However, when configuring the formula of criterion A using criterion S, the offset value previously provided in criterion S can be used identically in criterion A, but in the case of a specific offset, it may be applied differently or excluded. Alternatively, you can define new variables Srsrp_wus-entry and Srsrq_wus-entry completely independently of the criterion S, and then reflect the offsets described above to determine whether they satisfy a specific value provided in advance.

[0296] Although criterion A can be constructed based on the measurement values ​​of MR or LP-WUR, it can also be constructed using both measurements. For example, if the criterion resulting from channel measurement of MR is criterion MR and the criterion resulting from channel measurement of LP-WUR is criterion LR, criterion A can be considered satisfied only when both criterion MR and criterion LR are satisfied, or criterion A can be considered satisfied when only one of them is satisfied. In addition, criterion A can be constructed differently depending on when the entry is determined. For example, when determining the entry condition in the 804 process, criterion A may be configured to satisfy both criterion MR and criterion LR, or criterion A may be configured to satisfy criterion MR, and in the 808 process, criterion A may be configured with only criterion LR since the terminal's LP-WUR has experience or records of receiving signals such as LP-SS. As another method, when calculating the values ​​of Srsrp_wus-entry and Srsrq_wus-entry, a method may be considered that reflects both channel values ​​measured by both receivers, rather than applying only one of the values ​​measured by MR or calculated by LP-WUR. However, since the method may satisfy the entry condition even if the LP-WUR channel measurement value of the terminal is not good when the channel measurement value of the MR of a specific terminal is better than the channel measurement value of the MR of another terminal, the accuracy of predicting the LP-WUS reception capability of the terminal may be somewhat reduced.

[0297] This paper describes how a base station provides a threshold or offset to indicate the minimum channel measurement value that must be satisfied. It explains that this can vary depending on the LP-WUR type of the terminal or the signal used to perform the channel measurement. In addition, various coverage enhancement techniques can be introduced to provide LP-WUS in a wider coverage band (e.g., repetition or hopping transmission in the time or frequency dimension), and various thresholds that take these into account can be applied. For example, threshold_1 and threshold_2 can be provided, where threshold_1 indicates the degree to which a terminal can receive LP-WUS even without coverage enhancement techniques. In contrast, for terminals that do not satisfy threshold_1 but satisfy threshold_2, LP-WUS reception is possible only when coverage enhancement techniques are present. Therefore, if a separate threshold considering coverage enhancement techniques is provided, information about the coverage enhancement techniques must also be provided as LP-WUS-related information. For example, if threshold_2 is given as the threshold when considering 4 repeated transmissions, this means that the terminal can successfully receive LP-WUS only if it receives all 4 repeated LP-WUS transmissions when only threshold_2 is satisfied. If the coverage enhancement technology is related to the threshold utilized in the entry condition, whether or not the threshold is set can also be considered as whether or not the specific coverage enhancement technology of the base station is activated.

[0298] All of the examples and methods described above are not supported by selecting only one case, but multiple examples may be combined and supported depending on the conditions. In addition, the channel measurement utilized to determine the entry condition may be performed together with the RRM measurement process that the terminal is required to perform periodically, or may be performed independently. Specifically, when the MR measures the channel, the terminal may perform channel measurement to determine the entry condition while performing RRM measurement. However, when the LP-WUR is not permitted to perform RRM measurement on the terminal, the operation of measuring the channel by LP-WUR to determine the entry condition may be performed independently from the RRM measurement operation. From the terminal's perspective, how RRM measurement is performed is a terminal implementation matter, and just as there are minimum requirements that the terminal must comply with for measurement, when performing channel measurement to determine the entry condition, the specific measurement process is a terminal implementation matter, but there may be minimum requirements that must be satisfied, such as the number of samples filtered to obtain the measurement value, the time interval, or the number of cycles that must continuously satisfy a specific criterion.

[0299] In the case of an RRC CONNECTED terminal, since it periodically reports the channel status to the base station, the base station can directly determine whether LP-WUS can be activated based on the reported value and instruct the terminal to activate the LP-WUS function. In this process, since the channel measurement information that the terminal generally reports is based on what the MR performed, the terminal may be requested to report the channel measurement value measured by the LP-WUR. Alternatively, criterion A for a CONNECTED terminal may be provided, and the terminal may determine whether criterion A is satisfied based on the channel measurement value and report the result to the base station. At this time, the value measured by the terminal may be the same as the judgment of criterion A in the RRC IDLE or INACTIVE state, and the MR and LP-WUR may measure the channel together and then determine whether criterion A is satisfied based on the measured values ​​and report the result. However, it is assumed that the terminal and the base station have a common understanding of the specific details, such as which one was measured, MR or LP-WUR, and whether the signal used when measuring the channel by LP-WUR was SSS (in some cases, another signal transmitted by the base station, such as PSS in SSB, may be used) or LP-SS. Another method is for the base station to randomly transmit LP-WUS to the terminal that wants to activate the LP-WUS function and receive feedback from the terminal as to whether the signal can be properly received. That is, before activating the LP-WUS function of an RRC CONNECTED terminal, the base station transmits an LP-WUS to test the LP-WUS reception function of the terminal, and then reports to the base station whether the decoding failure of the LP-WUS or whether the LP-WUS itself was not received at all (detection failure).

[0300] In the above explanation, the term criterion A is used regardless of the RRC state of the terminal, but the specific conditions that constitute criterion A (e.g., a formula to be satisfied, a period for satisfying the condition, etc.) and the specific values ​​for satisfying the condition (e.g., a value provided by the base station, such as a threshold) may vary depending on the RRC state of the terminal for which the LP-WUS function is activated.

[0301] Meanwhile, as previously explained, current terminals are required to periodically measure the channel to perform functions such as cell reselection. This requirement may vary depending on the terminal's state. By measuring the channel, the terminal can determine the terminal's mobility state (High-mobility state, Medium-mobility state, Normal-mobility state) based on the number of cell reselection processes that occurred during a specific period. High mobility of the terminal makes it difficult to maintain LP-WUS activation for extended periods of time. Therefore, the LP-WUS function is likely to be repeatedly activated and deactivated. Therefore, using the LP-WUS function may not significantly contribute to power savings. Furthermore, if a fast-moving terminal activates the LP-WUS function but fails to properly receive the signal, it may impact system performance. Therefore, LP-WUS activation may be restricted for certain mobility states, or the offset value may be adjusted to apply a higher threshold. Alternatively, the introduction of new mobility states may be considered as one of the LP-WUS entry conditions. That is, if the cell reselection process occurs less than a certain number of times during a certain period immediately before the terminal activates the LP-WUS function, it can be determined that the mobility state is suitable for activating the LP-WUS function. If the cell reselection process occurs frequently, the terminal cannot activate the LP-WUS function even if other conditions are met.

[0302] In addition to the mobility status of the terminal, current terminals can also determine the channel measurement state based on the location status. Currently, if a terminal satisfies additional criteria set in addition to criterion S for a certain period of time, it is determined to be in a not-at-cell-edge state, which can partially relax the neighboring cell RRM measurement requirements. Therefore, determining whether the terminal is in a not-at-cell-edge state before activating the LP-WUS function can be considered as one of the entry conditions. For example, operations such as evaluating the entry condition only for terminals in the not-at-cell-edge state can be considered. Alternatively, terminals with the LP-WUS function can define a new not-at-cell-edge-LP-WUS state as a separate LP-WUS function entry condition, and determine whether the condition is satisfied before activating the LP-WUS function. However, the condition for determining the not-at-cell-edge-LP-WUS state can be distinct from criterion A, or it can be introduced as having the same role and configured in the same way as described above.

[0303] Meanwhile, as described in FIG. 7, there may be cases where LP-SS and LP-WUS are not activated at the same time. This can be understood as a case where the base station intentionally disables the LP-SS function or does not implement the LP-SS transmission function. If LP-SS is not transmitted, no attempt is made to determine the entry condition when it should be determined based on LP-SS, and thus the LP-WUS function is not activated. If the entry condition is not determined based on LP-SS (for example, when criterion A is determined only by MR), in the case of a terminal implemented with LP-WUR that must receive LP-SS, even if the LP-WUS function is activated, it may be difficult to successfully receive LP-WUS because LP-SS is not transmitted from the base station, and the operation of measuring the channel with LP-WUR is also likely not to be supported. Accordingly, in cases where the base station does not activate LP-SS, terminals that must receive LP-SS (e.g., terminals with only LP-WUR of type WUR-A) can be restricted from activating the LP-WUS function even if channel measurement conditions, etc. are satisfied.

[0304] In the above description, the entry condition for activating the LP-WUS function of the terminal was used to determine whether to activate the LP-WUS function of the terminal, i.e., whether to perform LP-WUS monitoring and stop the PDCCH monitoring that was previously in operation. In addition, a terminal with the LP-WUS function can relax the serving cell and neighboring cell channel measurement conditions that are previously required of the terminal in order to reduce power consumption. The conditions for relaxing the channel measurement conditions and the conditions for activating the LP-WUS function can be defined independently so that the terminal can determine them separately, or some or all of the conditions can be shared with the LP-WUS function activation conditions so that the terminal can be requested to perform at least a part of the methods for relaxing the channel measurement conditions when the entry condition is satisfied. Examples of methods for relaxing channel measurement conditions include: previously, in order to measure the channel of the serving cell, the terminal must measure the channel using MR every DRX cycle to determine whether criterion S is satisfied; however, the conditions can be relaxed by performing channel measurement of the terminal with the LP-WUS function activated using LR instead of MR, or by increasing the serving cell channel measurement cycle of the MR to N (N>1) DRX cycles instead of every cycle. In this case, when the terminal deactivates the LP-WUS function, the channel measurement conditions and channel measurement method of the terminal follow the operation of the existing terminal.

[0305] In the above explanation, it is considered that all parts that are not directly and clearly explained for terminals in RRC CONNECTED state and terminals in RRC IDLE and INATIVE states can be applied equally. However, the major difference is that in RRC CONNECTED, the base station can directly or indirectly signal only to terminals that the base station knows and can support, and the base station knows exactly what the terminal is doing, but in RRC IDLE and INACTIVE states, the terminal must directly determine the entry conditions, etc., and the base station does not know the result. Therefore, different methods may be applied depending on the RRC state of the terminal, or different terminal operations may be required accordingly.

[0306] The specific terms used in the above examples may be changed, and the methods described in the second embodiment may be used in combination with each other.

[0307] <Example 3>

[0308] The third embodiment of the present disclosure describes specific cases in which a terminal that has activated the LP-WUS function can no longer continue the LP-WUS function due to reasons such as a change in channel or movement of the terminal. In addition, the operation of the terminal when the entry condition is not satisfied or the LP-WUS function can no longer be continued is also described.

[0309] Basically, since the terminal can continue LP-WUS when the base station transmits LP-WUS, if the base station disables the LP-WUS function, the terminal no longer performs LP-WUS operation and can perform the operation of Fig. 6a or Fig. 6b, which was the operation of the existing terminal, depending on the RRC state of the terminal.

[0310] In cases where the LP-WUS function can no longer be maintained, as described above, the base station may instruct specific terminals to deactivate the LP-WUS function or may transmit information that the base station no longer supports the LP-WUS function. However, cases where the terminal can no longer maintain the LP-WUS function may also be considered.

[0311] As explained above, the terminal is required to periodically measure the serving cell channel, but the conditions for serving cell channel measurement when the terminal activates the LP-WUS function may be presented differently from the conditions for serving cell channel measurement of the existing terminal. For example, assuming that the serving cell channel measurement is performed only through LP-WUR, if the result of the channel measurement through LP-WUR is lower than a specific threshold (or does not meet a specific condition), the terminal may disable the LP-WUS function and perform the operation of the existing terminal from the next DRX cycle. In other words, it is possible to determine whether the exit condition is satisfied through the channel measurement result. The exit condition at this time may be the same as or different from criterion A configured for the entry condition. Specifically, since the UE, especially in the RRC IDLE or INACTIVE state, can be configured to perform channel measurement of the cell through LP-SS or SSB transmitted from the base station while the LP-WUR monitors the LP-WUS, it is highly likely that the LP-WUR will measure the channel rather than the MR to determine the exit condition. Therefore, if the entry condition includes the channel measurement of the MR, the corresponding part may be excluded from criterion A and a new criterion may be proposed to determine the exit condition. If criterion A is configured to consider only the case where the LP-WUR measures the channel, the standard for the channel measurement value for the exit condition may be the same as criterion A.That is, if the channel measurement value periodically measured while monitoring LP-WUS does not satisfy a specific criterion set by the base station, or conversely, if it satisfies it (for example, if the criterion is configured with a sign opposite to the entry condition), the LP-WUS monitoring function can be disabled and the existing operation can be performed.

[0312] Meanwhile, even for a terminal with the LP-WUS function activated, if the MR is set to operate periodically for purposes such as RRM measurement regardless of LP-WUS reception, a method of determining whether the MR can continue the LP-WUS function while performing other operations can be considered. However, since the cycle for MR to wake up may be too long to save power of the terminal, rather than including only the exit condition that the MR measures the channel to determine whether the LP-WUS function is disabled, combination with other additional methods (for example, determining whether the exit condition is satisfied in combination with the channel condition measured by LP-WUR) can be considered.

[0313] The exit condition for the LP-WUS function based on the channel measurement described above can be met simultaneously with the terminal performing the 805 process. Other exit conditions that can be met during the 805 process may include a timer-based exit condition. A terminal monitoring LP-WUS may recognize that LP-WUS reception may not be smooth if its corresponding LP-WUS is not received for a long period of time. For example, although the channel condition based on LP-SS or SSB is good, if the threshold provided by the base station does not match well, or the coverage of the signal used for channel measurement does not match the coverage of the LP-WUS, LP-WUS reception may fail even though the channel measurement is successful, resulting in a case where LP-WUS is not received at all (detection failure). To prevent such cases as much as possible, timer-based actions such as returning to default operation or sending a notification to the base station if LP-WUS reception is not achieved for a long period of time can be considered. At this time, the types of timers that can be considered can be broadly divided into two types.

[0314] - First timer (timer 1): This timer detects when the terminal continuously monitors the LO where LP-WUS is transmitted every cycle, but fails to detect LP-WUS for a long period of time. This timer starts from the time LP-WUS is activated and applies to cases where no LP-WUS is detected before the timer expires. In other words, this is a case of detection failure where it is not possible to determine whether the terminal should be woken up through LP-WUS, as well as whether other terminals are woken up. There are two main reasons for this: the base station may have transmitted it, but the terminal may not have actually received it, or the base station may not have transmitted any LP-WUS on the LO because there are no terminals to wake up. If the base station transmits at least one LP-WUS for each period that the terminal monitors so that the terminal can determine whether detection failure has occurred, the terminal can operate the MR immediately when detection failure occurs and repeat the existing operation process (Fig. 6a or Fig. 6b) or perform the process of Fig. 9. The contents of Fig. 9 will be described in detail later. However, in order to save energy and avoid unnecessary use of resources, if the base station operates by not transmitting LP-WUS when there is no terminal to wake up, it is difficult to distinguish whether the base station actually did not transmit or the terminal's LP-WUS detection failure occurred. Therefore, when an LP-WUS detection failure occurs for a long period of time and no LP-WUS-related information can be obtained, the terminal's MR can be operated based on timer 1 that the base station sets in advance or that is provided in the standard.If the device receives even one LP-WUS that wakes up another terminal, including itself, before the timer expires, the timer is reset and starts counting again from that point.

[0315] - Second timer (timer 2): The second timer detects when LP-WUS is received but LP-WUS to wake up the UE is not received for a long period of time. After receiving LP-WUS, the UE checks whether its (sub)group should wake up. If PDCCH monitoring is not instructed for its (sub)group, it can continue to maintain UDS mode. In this case, the base station may not actually instruct the (sub)group, but it may also be a case where the UE made an incorrect judgment in step 806 due to a decoding failure. Therefore, even if the UE receives LP-WUS, if the MR does not operate for a long period of time due to an instruction through LP-WUS, that is, if it does not move from step 806 to 807 for a long period of time, a problem may occur. Therefore, timer 2 can be considered as an exit condition to prepare for this. The timer is started when the terminal activates the LP-WUS function, and is reinitialized when the terminal is instructed to perform a PDDCH reception operation due to LP-WUS, i.e., when process 807 is performed, and then the operation of restarting timer 2 is repeated when the LP-WUS monitoring operation is restarted through process 805. If process 807 is not performed until timer 2 expires, the terminal considers that the exit condition related to timer2 is satisfied and repeats the operation of the existing terminal of FIG. 6a or 6b or performs the operation of FIG. 9 to determine whether the entry condition is satisfied again.

[0316] At this time, only one of timer 1 and timer 2 may be utilized as an exit condition, or the two timers may be combined to operate as an exit condition. For example, the exit condition may be considered satisfied when either timer 1 or timer 2 expires, or the exit condition may be considered satisfied when both timer 1 and timer 2 expire. In addition, instead of providing the same function as the corresponding timer, it may be provided based on the LO cycle or DRX cycle. For example, if the exit condition is satisfied when no LP-WUS that the terminal should detect has been detected until L LO cycles have passed, and the terminal must perform the existing operation or the operation of FIG. 9, this can be viewed as the same method as using timer 1.

[0317] Similar to the entry conditions described in the second embodiment, the corresponding exit conditions may be applied differently to terminals in RRC IDLE or INACTIVE states and terminals in RRC CONNECTED states. For example, in the case of an RRC CONNECTED terminal, since the base station periodically receives reports on the channel status of the terminal, the terminal may not be required to directly determine and act based on channel measurement values. However, methods such as signaling when the base station determines that the terminal should deactivate the LP-WUS function or timer-based operations may be applied in the same manner.

[0318] At this time, when the terminal is performing an existing operation or must re-evaluate the entry condition while performing an existing operation, all values ​​for the timers used to determine the entry condition are initialized. In addition, it can be seen that the timers used while operating LP-WUS are also initialized.

[0319] Meanwhile, when data to be transmitted arises while the terminal is activating the LP-WUS function, the terminal may want to transmit an uplink signal. If the terminal is in the RRC IDLE or INACTIVE state, the terminal will deactivate the LP-WUS function on its own and perform a procedure to transition the RRC state to the RRC CONNECTED state. The terminal can determine the time to deactivate the LP-WUS function on its own, but the terminal must unconditionally perform either the operation of FIG. 8 for monitoring LP-WUS or the operation of FIG. 6a for paging the existing terminal. However, if there is a period in which the terminal does not need to monitor PO, only the procedure for RRC CONNECTION may be performed.

[0320] For a terminal in RRC CONNECTED state, LP-WUS monitoring for uplink transmission can operate independently or dependently. If the terminal has an uplink transmission to be performed and attempts to transmit uplink to the base station during the ON duration period or other periods in which uplink transmission is allowed, the terminal may determine that the LP-WUS function is no longer needed and may deactivate the LP-WUS function on its own. At this time, the base station may also recognize that the LP-WUS function was deactivated at the moment the terminal transmitted the uplink and may issue necessary instructions to the terminal (e.g., signaling to re-activate the LP-WUS function).

[0321] Meanwhile, since it is unclear whether the base station has accurately received the uplink signal from the terminal, the deactivation of the LP-WUS function and the deactivation time may not match. Therefore, the terminal may maintain the operation of monitoring LP-WUS until the base station responds after transmitting the uplink, and may then determine the operation according to the instruction of the base station. For example, if the base station sends a signal to deactivate the LP-WUS function or signals to no longer perform the C-DRX operation after the terminal transmits the uplink, the terminal may recognize that the LP-WUS function has been deactivated and perform the operation of FIG. 9.

[0322] In addition, as described in the previous embodiment, if it is determined that the terminal performed step 807 after being instructed to receive PDCCH in step 806 and performed step 807 due to a decoding failure or false alarm of the terminal, the entry condition may be checked again to determine whether to continue the LP-WUS function, but this may be used as an exit condition to omit step 808, deactivate the LP-WUS monitoring operation, return to the operation of the existing terminal, and perform the operation of FIG. 6a or FIG. 6b, or FIG. 9.

[0323] The operation of a terminal when the terminal does not satisfy the conditions for activating the LP-WUS function in steps 804 and 808, or when the LP-WUS function is deactivated due to a change in the status of the terminal or base station, is described in FIG. 9. FIG. 9 is a diagram illustrating an example of an operation procedure in which the LP-WUS function is deactivated due to a terminal that does not satisfy the entry conditions for activating the LP-WUS function or an exit procedure.

[0324] Referring to FIG. 9, the operations can be differentiated depending on the RRC status of the terminal in step 900. If the terminal is in RRC IDLE or RRC INACTIVE, steps 602 to 607 described in FIG. 6a can be performed through step 901. At this time, it can be assumed that the system information required for obtaining the paging information in step 601 has already been acquired by the terminal. The terminal can continue to determine the entry conditions while performing its original operation.

[0325] The UE must check whether it can re-evaluate the entry condition in step 902. This may include whether the base station has still activated the LP-WUS function or whether the UE's state has changed to a state that is not sufficient to determine the entry condition. For example, if the UE's mobility state has changed to a state that does not meet the entry condition for activating the LP-WUS function, the UE can be considered to be in a state where it cannot determine the entry condition for activating the LP-WUS function. Alternatively, a constraint may be placed on re-evaluating the entry condition after a certain period of time for a UE that has not met the entry condition even once. For example, if at least N i-DRX cycles are required to measure the channel value required to determine criterion A, and there is a constraint that the channel value previously used to determine criterion A cannot be used to re-evaluate the entry condition, then the entry condition can be re-evaluated after at least N i-DRX cycles have passed since the entry condition was not met. If the terminal is not in a state where it can re-evaluate the entry conditions, it performs step 901 and repeats step 902 as long as the terminal is willing to use the LP-WUS function. If the terminal is in a state where it can re-evaluate the entry conditions, the terminal starts from step 804 of FIG. 8 to re-evaluate the entry conditions for activating the LP-WUS function through step 903.

[0326] If the terminal is in the RRC CONNECTED state, the terminal can determine whether the base station has disabled the C-DRX function through process 904. If the C-DRX function itself has been disabled, the terminal can perform PDCCH monitoring in all configured search spaces through process 908. Even if the C-DRX function of the terminal is disabled, the base station can request the terminal to activate the LP-WUS function, but in FIG. 9, it is assumed that such a case is not considered, and a case in which the LP-WUS function cannot be activated before the base station activates the C-DRX is described.

[0327] In the case of a terminal in RRC CONNECTED state when the base station has not deactivated the C-DRX function, since the base station can often directly instruct the terminal to activate or deactivate the LP-WUS function, when the terminal receives the PDCCH or PDSCH transmitted by the base station and an instruction to activate the LP-WUS function of the terminal is transmitted, the entry condition can be considered satisfied in step 906. If, as described in Embodiment 2, other entry conditions, such as a timer, are combined to determine whether the RRC CONNECTED terminal satisfies the entry condition, step 907 can be passed from step 906 if the condition is satisfied. If the entry condition is not satisfied or there is no direct or indirect instruction from the base station, step 905 is repeated. For a terminal with the LP-WUS function activated, the LP-WUS monitoring operation starts in step 907. At this time, it can be considered that the terminal has already acquired the C-DRX information and LP-WUS settings set for the terminal.

[0328] In the present disclosure, the contents of FIGS. 7, 8, and 9 can be equally applied to terminals configured with eDRX. Specifically, the LP-WUS monitoring time, specific values ​​of entry conditions, etc. of terminals configured with eDRX may differ from those of terminals configured with i-DRX, but candidate technologies and methods that can configure entry and exit conditions determined by terminals configured with eDRX are no different from those of terminals configured with i-DRX.

[0329] The operation and entry / exit conditions of a terminal having the LP-WUS function described in the present disclosure can be individually defined as the minimum conditions for the terminal to perform a specific operation, while in another way, they can be considered as conditions that the terminal must satisfy in order to define a specific state of the terminal and move to the corresponding state. For example, state 805 of FIG. 8 can be defined as the LP-WUS monitoring state, state 807 as the wake-up state, and the state performing the operation of FIG. 6a or 6b or FIG. 9 as the fallback state, and conditions for transitioning to each state can be defined. In other words, it can be considered which entry or exit conditions must be satisfied in order to transition to another state. For example, in order to transition from the fallback state to the LP-WUS monitoring state, the entry conditions defined for the corresponding state transition must be satisfied, and the specific configuration of the entry conditions can be applied in the same way as the contents described in process 804 of FIG. 8 or process 902 or 906 of FIG. 9. In summary, in order to transition from the LP-WUS monitoring state or wake-up state to the fall back state, the exit conditions described above must be satisfied, and in order to transition from the wake-up state or fall back state to the LP-WUS monitoring state, the entry conditions described above must be satisfied. Meanwhile, if the following states are defined to simply configure the entry and exit conditions, the operations that the terminal must perform for each state include the operations of the terminal described in FIG. 8, and other operations that the terminal must perform, such as RRM measurement, may also be added.

[0330] The specific terms used in the above examples may be modified, and the contents of the present disclosure are not limited to the examples described herein. At least one of the methods of the first embodiment, the second embodiment, or the third embodiment of the present disclosure may be used in combination with each other.

[0331] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0332] The invention of the present disclosure is not limited by the contents described in the above-described FIGS. 7, 8 to 9, and the contents of FIGS. 7, 8 to 9 can be combined with the first embodiment or / and the second embodiment or / and the third embodiment, and each step of FIGS. 7, 8 to 9 can be omitted, or other steps can be added, or the order can be changed so that the present invention can be performed.

[0333] FIG. 10 is a block diagram illustrating an example of the structure of a terminal according to one embodiment of the present disclosure.

[0334] Referring to FIG. 10, the terminal (1000) may include a transceiver (1001), a control unit (e.g., a processor) (1002), and a storage unit (e.g., a memory, 1003). The transceiver (1001), the control unit (1002), and the storage unit (1003) of the terminal (1000) may operate according to at least one or a combination of the methods corresponding to the above-described embodiments. However, the components of the terminal (1000) are not limited to the illustrated example. According to other embodiments, the terminal (1000) may include more or fewer components than the components described above. In addition, in certain cases, the transceiver (1001), the control unit (1002), and the storage unit (1003) may be implemented in the form of a single chip.

[0335] The transceiver (1001) may, according to one embodiment, be composed of a transmitter and a receiver. The transceiver (1001) may transmit and receive signals with a base station. The signals may include control information and data. The transceiver (1001) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts the received signal. The transceiver (1001) may receive a signal through a wireless channel and output the signal to the control unit (1002), and may transmit a signal output from the control unit (1002) through the wireless channel.

[0336] The control unit (1002) may control a series of procedures that the terminal (1000) may perform according to the embodiments of the present disclosure described above. For example, the control unit (1002) may perform or control the operation of the terminal to perform at least one or a combination of methods according to the embodiments of the present disclosure. The control unit (1002) may include at least one processor. For example, the control unit (1002) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer (e.g., an application).

[0337] The storage unit (1003) can store control information (e.g., setting information for WUS set to the terminal (1000)) or data, and can have an area for storing data required for controlling the control unit (1002) and data generated during control in the control unit (1002).

[0338] Although not shown, the terminal (1000) may further include a WUR. The WUR may be included in the transceiver (1001) or may exist as a separate receiver without being included in the transceiver (1001).

[0339] FIG. 11 is a block diagram illustrating an example of the structure of a base station according to one embodiment of the present disclosure.

[0340] Referring to FIG. 11, a base station (1100) may include a transceiver (1101), a control unit (e.g., a processor) (1102), and a storage unit (e.g., a memory) (1103). The transceiver (1101), the control unit (1102), and the storage unit (1103) of the base station (1100) may operate according to at least one or a combination of methods corresponding to the above-described embodiments. However, the components of the base station (1100) are not limited to the illustrated example. According to other embodiments, the base station (1100) may include more or fewer components than the components described above. In addition, in certain cases, the transceiver (1101), the control unit (1102), and the storage unit (1103) may be implemented in the form of a single chip.

[0341] The transceiver (1101) may, according to one embodiment, be composed of a transmitter and a receiver. The transceiver (1101) may transmit and receive signals with a terminal. The signals may include control information and data. The transceiver (1101) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-downconverts the received signal. The transceiver (1101) may receive a signal through a wireless channel and output the signal to the control unit (1102), and may transmit a signal output from the control unit (1102) through the wireless channel.

[0342] The control unit (1102) may control a series of procedures so that the base station (1100) can operate according to the embodiments of the present disclosure described above. For example, the control unit (1102) may perform or control the operation of the base station to perform at least one or a combination of methods according to the embodiments of the present disclosure. The control unit (1102) may include at least one processor. For example, the control unit (1102) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer (e.g., an application).

[0343] The storage unit (1103) can store control information (e.g., setting information for WUS), data, control information received from a terminal, or data, and can have an area for storing data required for controlling the control unit (1102) and data generated during control in the control unit (1102).

[0344] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0345] While the detailed description of the present invention has described specific embodiments, it is clear that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

[0346] In a wireless communication system, a method for a terminal to perform communication can receive information related to a Wake Up Signal (WUS). The method can determine whether to activate a WUS reception function based on the information related to the WUS. If the WUS reception function is activated, the method can monitor the WUS for PDCCH (Physical Downlink Control Channel) reception. The method can receive the PDCCH based on the monitoring results.

[0347] A device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0348] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0349] According to one embodiment of the present disclosure, a method performed by a terminal in a wireless communication system may include a step of transmitting terminal capability information related to a Low Power Wake Up Signal (LP-WUS) to a base station. The method may include a step of receiving an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information from the base station. The method may include a step of monitoring the LP-WUS for PDCCH (Physical Downlink Control Channel) reception when a reception function of the LP-WUS is activated. The method may include a step of receiving the PDCCH based on a monitoring result.

[0350] In one embodiment, the method may include receiving a Medium Access Control Control Element (MAC CE) message including activation information of an LP-WUS. The method may include re-monitoring the LP-WUS for PDCCH reception based on the activation information included in the MAC CE.

[0351] In one embodiment, the method may include receiving system information including configuration information related to LP-WUS from a base station. In one embodiment, LP-WUS may be identified as activated based on the reception of the system information.

[0352] In one embodiment, when the LP-SS (Low Power Synchronization Signal) for synchronization operation for receiving the LP-WUS is disabled, the receiving function of the LP-WUS can be activated.

[0353] In one embodiment, the terminal capability information may include a type for the terminal's Wake Up Receiver (WUR).

[0354] In one embodiment, the method may set a timer for the LP-WUS. The method may determine whether to activate the receiving function of the LP-WUS based on the timer.

[0355] In one embodiment, when receiving a PDCCH based on a monitoring result, reception of a PDCCH other than the PDCCH may not be performed through the LP-WUS.

[0356] A terminal performing communication according to one embodiment of the present disclosure may include a transceiver and at least one processor connected to the transceiver. The at least one processor may transmit terminal capability information related to a Low Power Wake Up Signal (LP-WUS) to a base station. The at least one processor may receive an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information from the base station. The at least one processor may monitor the LP-WUS for Physical Downlink Control Channel (PDCCH) reception when a reception function of the LP-WUS is activated. The at least one processor may receive the PDCCH based on a monitoring result.

[0357] According to one embodiment of the present disclosure, in a method for a base station to perform communication in a wireless communication system, the method may include a step of receiving terminal capability information related to a Low Power Wake Up Signal (LP-WUS) from a terminal. The method may include a step of transmitting an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information to the terminal. The method may include a step of transmitting a Physical Downlink Control Channel (PDCCH) based on a monitoring result for the LP-WUS for PDCCH reception when the LP-WUS is activated.

[0358] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method for a terminal to perform communication in a wireless communication system, A step of transmitting terminal capability information related to LP-WUS (Low Power Wake Up Signal) to a base station; A step of receiving an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information from the base station; When the receiving function of the above LP-WUS is activated, a step of performing monitoring for the LP-WUS for receiving a PDCCH (Physical Downlink Control Channel); and A method comprising: receiving the PDCCH based on the monitoring result; 2. In paragraph 1, A step of receiving a MAC CE (Medium Access Control Control Element) message including activation information of the above LP-WUS; and A method comprising: a step of re-monitoring LP-WUS for PDCCH reception based on activation information included in the MAC CE; 3. In paragraph 1, A step of receiving system information including setting information related to the LP-WUS from the base station; including; A method wherein the LP-WUS is identified as activated based on receipt of the above system information.

4. In paragraph 1, A method in which the reception function of the LP-WUS is activated when the LP-SS (Low Power Synchronization Signal) for the synchronization operation for reception of the LP-WUS is deactivated.

5. In paragraph 1, A method wherein the terminal capability information includes a type for a WUR (Wake Up Receiver) of the terminal.

6. In paragraph 1, A step of setting a timer for the above LP-WUS; and A method comprising: a step of determining whether to activate the receiving function of the LP-WUS based on the timer; 7. In paragraph 1, A method in which, when the PDCCH is received based on the monitoring result, reception of a PDCCH other than the PDCCH is not performed through the LP-WUS.

8. In a terminal performing communication in a wireless communication system, Transmitter and receiver; and At least one processor connected to the transceiver, wherein the at least one processor comprises: Transmit terminal capability information related to LP-WUS (Low Power Wake Up Signal) to the base station, Receive an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information from the base station, When the receiving function of the above LP-WUS is activated, monitoring is performed on the LP-WUS for PDCCH (Physical Downlink Control Channel) reception. A terminal that receives the PDCCH based on the above monitoring results.

9. In the 8th paragraph, the at least one processor, Receive a MAC CE (Medium Access Control Control Element) message containing activation information of the above LP-WUS, A terminal that re-monitors LP-WUS for PDCCH reception based on activation information included in the MAC CE.

10. In the 8th paragraph, the at least one processor, Receive system information including setting information related to the LP-WUS from the base station, A terminal, wherein the LP-WUS is identified as activated based on receipt of the above system information.

11. In paragraph 8, A terminal in which the reception function of the LP-WUS is activated when the LP-SS (Low Power Synchronization Signal) for synchronization operation for reception of the above LP-WUS is deactivated.

12. In paragraph 8, The terminal capability information includes the type of WUR (Wake Up Receiver) of the terminal.

13. In the 8th paragraph, the at least one processor, Set a timer for the above LP-WUS, A terminal that determines whether to activate the receiving function of the LP-WUS based on the above timer.

14. In paragraph 8, A terminal in which, when receiving the PDCCH based on the monitoring result, reception of a PDCCH other than the PDCCH is not performed through the LP-WUS.

15. In a method for a base station to perform communication in a wireless communication system, A step of receiving terminal capability information related to LP-WUS (Low Power Wake Up Signal) from a terminal; A step of transmitting an RRC (Radio Resource Control) message including information related to the LP-WUS and activation information to the terminal; and A method comprising: a step of transmitting a PDCCH (Physical Downlink Control Channel) based on a monitoring result for the LP-WUS for receiving the PDCCH when the LP-WUS is activated;

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